There are no statistics available for this player Thanks for visiting The use of software that blocks ads hinders our ability to serve you the content you came here to enjoy We ask that you consider turning off your ad blocker so we can deliver you the best experience possible while you are here ABU DHABI, U.A.E. – Hammad Hanif Pasha, an IT consultant who has lived in Abu Dhabi since 2010, feels like the Emirate’s government services are always within reach, thanks to TAMM The AI-powered TAMM app puts about 950 Abu Dhabi government services at his fingertips He says it has improved his quality of life by making it so much easier – no more fighting traffic to get to an appointment “I haven’t been in a government building in four or five years,” he said who made more than 10 million transactions in the past year ranging from paying traffic fines to getting a marriage license finding answers to even the most complex government processes has become effortless – as simple as sending a text message Pasha cited car registration as one of the most convenient features “It used to take three or four days before – you had to go for the inspection of the car you had to make sure that the actual registration happened on the same day that the insurance started.” you had to get another one-day insurance policy to make it match.” other than for the actual inspection of the car The AI chatbot recommended the right type of insurance policy and synchronized it with registration TAMM is a key initiative driven by His Highness Sheikh Mohamed bin Zayed Al Nahyan President of the United Arab Emirates and Ruler of Abu Dhabi the largest Emirate in the United Arab Emirates he started a drive to centralize government services and make them more accessible and service-oriented the idea of making government services accessible anytime took hold and the efforts towards shaping TAMM started The services TAMM provides range from paying fines from the ubiquitous traffic cameras along Abu Dhabi’s roadways (which and basically anything else that one might need from a government office – like a visa renewal TAMM is more than just an app. What makes it unique is the fact that all these different government entities in Abu Dhabi came together to create a single, integrated platform. The TAMM platform is powered by Microsoft Azure OpenAI Service and G42 Compass 2.0 G42 is an Emirates-based company with sovereign cloud service and Compass 2.0 is a next-generation enterprise AI platform offered by the company that provides access to many open-source models which is billed as the world’s highest-performing Arabic Large Language Model Microsoft made a strategic investment in G42 to co-innovate and deliver advanced AI solutions with Microsoft Azure for various industries and markets across the Middle East Alhammadi said that TAMM was designed to remove the barriers between government workers and the citizens residents and businesses who need services “You know that desk they were sitting behind or that window that separated them from people — those are gone,” he said on a work trip when an immigration agent told her that her visa had not been fully processed and that she couldn’t leave and when she couldn’t find an answer right away it’s getting updated now.’ — and I was on my way.” uses the TAMM app for everything from visa renewals to paying her traffic fines has the feel of a tech startup in a loft space with large open meeting areas and big screens updating with fresh user satisfaction data Alhammadi said that the agile approach is purposeful and adds to the satisfaction of TAMM employees “That aspect of the work makes it exciting because it’s not a routine job everyone’s staying up late at night and we’re testing to make sure we have the best quality of services and features before they go online.” One of the recent additions is a photo reporting app where people can take a photo of a problematic situation – a pothole or a broken traffic light – and the AI assistant will help fill out the report then update the person who reported the incident on the progress of repairing the problem Alhammadi pointed out that in addition to making government more accessible TAMM is saving thousands of car trips and lots of paper He showed a visitor his TAMM app – the utility bill and traffic fines to pay (yes everyone has them) – and a handy feature that shows his year-in-review activity report I applied for more than 70 government services in TAMM we saved 6,000 trees – over 12 million government services used.” a lifelong Abu Dhabi resident and an IT specialist the most impressive aspect of the app is how it has helped him and his son navigate government services for People of Determination (POD) the Emirati term for people with disabilities Khalid has dyslexia and has been diagnosed with a spectrum of autism Hamed said that the process of getting a POD card which is needed to qualify for special services this was often a process that could take a month and was fraught with uncertainty “It was very easy and very smooth through TAMM,” Hamed said “And if there was a situation where they didn’t have an answer someone would find out and get the answer to me One of the things that I really like is that they follow up said that for people who don’t have smartphones or for some reason can’t use them there are service centers where the same unified approach to government services is available where a TAMM agent comes to the door to help secure any needed services He said the newest version of TAMM with the AI assistant makes using it even easier ‘How can I help you today?’ Here I can continue my recent conversations and here I can ask what’s the latest on my request.” Aljasmi said that in the coming weeks users will be able to have spoken conversations with the AI assistant and ask it to take care of tasks Hammad Hanif Pasha said that even though TAMM is just an app in his phone he feels like in the bigger picture it’s a way that the Abu Dhabi government is empowering its community by embracing the latest technology “It’s really changed things for the better,” he said “It doesn’t just shape the future of the country Our editors will review what you’ve submitted and determine whether to revise the article Lebedev Physics Institute of the Soviet Academy of Sciences (FIAN) where he organized and headed the theoretical division Tamm developed this theory more fully in a paper published in 1939 and Cherenkov received the 1958 Nobel Prize for Physics This website is using a security service to protect itself from online attacks The action you just performed triggered the security solution There are several actions that could trigger this block including submitting a certain word or phrase You can email the site owner to let them know you were blocked Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page Estonian disc golfer Albert Tamm has been recognised as Athlete of the Month for November 2024 following his crucial role in Estonia's successful defence of their World Team Disc Golf Championship title The accolade comes as a testament to Tamm’s leadership and skill as well as the remarkable unity of the Estonian team throughout the tournament Tamm highlighted the team's solidarity and strategic adaptability as key to their dominance in Perth “We approached every match with the mindset that we win and lose as a team,” he said Estonia's balanced roster allowed them to adjust effectively to their diverse opponents a factor that proved decisive in their consistent performance Tamm noted that the team faced stiff competition particularly in a tense match against Thailand things can change very quickly,” he explained the team managed to regain control by refocusing and embracing the moment Estonia’s success adds momentum to their preparations for The World Games 2025 in Chengdu While Tamm has not confirmed his participation he expressed confidence in the Estonian Disc Golf Association’s ability to select a competitive roster “The victory shapes our approach moving forward but the team for Chengdu will be chosen with careful consideration,” he noted Estonia's back-to-back victories have reinforced its position as a global leader in disc golf Tamm credited fellow Estonian Kristin Tattar for her groundbreaking influence on the women’s divisions as well as the “Snäp!” youth program created by the Estonian Disc Golf Association which has gained international recognition “By staying true to our values and doing what we believe is best for the sport we inspire others to aim higher,” Tamm emphasised For young Estonians dreaming of international success Tamm had a clear message: take the initiative you need to take full responsibility and make it happen yourself,” he advised underscoring the importance of determination and self-promotion Albert Tamm’s recognition as Athlete of the Month reflects not only his individual talent but also the collective strength of Estonian disc golf The International World Games Association (IWGA) is a non-profit-making international sports organisation recognised and supported by the International Olympic Committee The IWGA comprises 40 International Member Sports Federations It administers and promotes The World Games (TWG) a multi-sport event held every four years that features around 35 sports on its programme The next edition of TWG will be in Chengdu (CHN) from 7-17 August 2025 5,000 participants from more than 100 countries are expected to take part in this 12th edition The latest Games were hosted by Birmingham For more information, please contact the IWGA Media and Communication team: [email protected], Tel: +41 21 311 12 97, or visit our web site. This website is using a security service to protect itself from online attacks. The action you just performed triggered the security solution. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. You can email the site owner to let them know you were blocked. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. Dining For those still shedding tears over the closure of Nomad inside Tamm Avenue Bar (1227 Tamm) there is reason to dry your eyes: The Dogtown bar has announced a new tenant—one with a loyal following that’s been in search of a home for the past four years.  That forthcoming tenant is none other than Byrd & Barrel the popular fried chicken and “nugs” concept opened by Tamm Avenue Bar co-owner Bob Brazell in 2015 Although no exact opening date has been given Byrd & Barrel is anticipated to open in the coming weeks Louis Dining In and Dining Out newsletters to stay up-to-date on the local restaurant and culinary scene The bar announced the news on Instagram: “We’re excited to announce that we’ll be opening a full-service brick-and-mortar restaurant in the former Nomad space,” Tamm Avenue Bar’s Instagram post reads “The support for our first Byrd & Barrel Sunday at Nick’s Pub was unbelievable so we’ve decided to give you more of what you want.” Brazell notes that the decision to reopen Byrd & Barrel inside of Tamm Avenue came about quickly and I sort of feel like I am drinking out of a firehose let’s bring it on,” says Brazell “It’s a good feeling to have it back again.” Brazell first opened Byrd & Barrel in 2015 inside a former Popeye’s Chicken on Jefferson Avenue near Cherokee Street it quickly became one of the city’s most beloved eateries and maintained a loyal following for five years Pandemic-related stressors forced Brazell and his team to reevaluate their business operations they made the difficult decision to temporarily close both Byrd & Barrel and his other restaurant The goal was to reopen at some point. While that happened for The Tenderloin Room in July 2021, Byrd & Barrel has largely remained on hold since. Although the concept was slated to reopen on Hampton Avenue “We were looking to move Byrd to a larger location before the pandemic; I signed the paperwork at the title company for the Hampton location on March 12 then went back to celebrate at Tamm only to look up at the televisions and see that all of the restaurants in the city were closing and the world was ending,” Brazell says Brazell and his partners still moved forward with their plans to move Byrd & Barrel into the Hampton building; they repaired the roof their priority was keeping all of their employees on the payroll and they had to shift money from renovations to keeping their other businesses running This made renovations slow-going and left customers to wonder when they would be able to again enjoy Byrd & Barrel’s delicious fried bird and other comfort food offerings beyond its stand at Enterprise Center.  “The signs are getting changed, we’re doing some painting and going to our storage unit to get all the funky artwork we had at the original Byrd & Barrel so it will look like the old one,” says Brazell. “We will start out with lunch and dinner and sort of ease into it, but we’ll quickly start pressing as hard as we can. As long as people show up, we will be here and ready for it.”  Listen Here Listen Here Listen Here Listen Here DINING NEWSLETTERS Subscribe to the St. Louis Dining In and Dining Out newsletters to stay up-to-date on the local restaurant and culinary scene. Start your mornings with a fresh take on the day’s top local news from Sarah Fenske and Ryan Krull. No spam, you can unsubscribe anytime you want. Our award-winning content brings readers revealing profiles Start your mornings with a fresh take on the day’s top local news Metrics details Next-generation light-emitting applications such as displays and optical communications require judicious control over emitted light including intensity and angular dispersion this remains a challenge as conventional methods require cumbersome optics we report highly directional and enhanced electroluminescence from a solution-processed quasi-2-dimensional halide perovskite light-emitting diode by building a device architecture to exploit hybrid plasmonic-photonic Tamm plasmon modes By exploiting the processing and bandgap tunability of the halide perovskite device layers we construct the device stack to optimise both optical and charge-injection properties leading to narrow forward electroluminescence with an angular full-width half-maximum of 36.6° compared with the conventional isotropic control device of 143.9° and narrow electroluminescence spectral full-width half-maximum of 12.1 nm The device design is versatile and tunable to work with emission lines covering the visible spectrum with desired directionality thus providing a promising route to modular and directional operating light-emitting devices which makes them promising candidates for the next generation lighting technologies To fully exploit the properties of these materials in a range of light applications absolute control of the emission properties via the implementation of refined light management methods will be crucial we employ a halide perovskite light-emitting diode (PeLED) device driven by Tamm plasmon modes for precise angular and colour control we tune the Tamm plasmon resonance wavelength to match the perovskite electroluminescence (EL) peak and thus confine the Tamm plasmon modes within the entire perovskite layer The Tamm plasmon resonance modes enhance the perovskite EL in forward direction by a factor of 1.8 compared to the reference and outcouple light modes efficiently with narrow and controllable angular dispersion with angular full-width half-maximum (FWHM) of 36.6° compared to 143.9° for the control the Tamm plasmon modes show stronger confinement of the electromagnetic field than the full photonic microcavities thus attractive for PeLEDs as the perovskite film is typically thin The approach is versatile and tuneable across different emitting energies and angles thus opening avenues for wider applications in display and light sources which require fine control of the angular dispersion and intensity of emitted light a Cross-sectional HAADF-STEM image of the perovskite-based Tamm plasmon structure Left: Magnified image of the metal-quasi-2D perovskite interface A similar structure is fabricated as the reference-perovskite structure (without TiO2/SiO2 layer pairs) to ensure results are not affected by unwanted effects The thickness of each layer is TiO2 = (70 ± 2) nm b EDX chemical map of perovskite-based Tamm plasmon structure The observed halo features at the titanium (Ti)-rich interface are found to be a slight compositional gradient of Ti while the oxygen composition remains constant at the interface \(\frac{{\left|E\right|}^{2}}{{\left|{E}_{0}\right|}^{2}}\) of the narrow-angle-Tamm-plasmon-perovskite structure d Experimental optimisation of perovskite-based Tamm-plasmon structure by varying the perovskite thicknesses between 20 nm to 54 nm (Tamm plasmon resonance wavelength best fitted with transfer matrix model to estimate thickness of perovskite) Tamm plasmon resonance dip acquired from reflectance measurements at 8° PL of quasi-2D perovskite thin film on glass is shown as dashed line e Tamm plasmon resonance wavelength at 8° versus perovskite film thickness Perovskite thickness is measured under AFM (solid line) and estimated from Tamm plasmon resonance wavelength best fitted with simulation (dashed line) Inset: schematic of the perovskite-based Tamm-plasmon structure with a green arrow indicating the quasi-2D perovskite layer it is seen that the experimentally measured Tamm plasmon resonance linearly red shifts from 485 nm to 565 nm as the perovskite thickness increases from 20 nm to 54 nm we found that a perovskite thickness of 26 nm in the perovskite-based Tamm plasmon stack gives a matching Tamm plasmon resonance with the perovskite film PL wavelength (dashed black line) Experimental angular photoluminescence (PL) results and simulations of (a–c) reference perovskite stack (d–f) narrow-angle-Tamm-plasmon-perovskite structure with quasi-2D perovskite thickness of 26 nm and (g–i) wide-angle-Tamm-plasmon-perovskite structure with quasi-2D perovskite thickness of 50 nm g PL intensity of each samples collected at increasing angle of 0° e Detection angle against PL of reference-perovskite stack and narrow-band-Tamm-plasmon-based perovskite structure with PL spectra integrated from 480 nm to 540 nm h Detection angle against PL of wide-angle-Tamm-plasmon-perovskite structure with PL spectra integrated between 505 nm to 565 nm Since all samples are excited at the same power density the integrated PL are comparable among the three samples i Finite-difference time-domain simulation of angular output power of each structure PL intensity of all configurations normalised to the PL intensity of narrow-angle-Tamm-plasmon-perovskite structure (see colour bars) the narrow-angle-Tamm-plasmon-perovskite exhibits sharp emission directionality with angular FWHM of 44.7° compared to 124.5° for the reference perovskite with the same excitation power density (excited with a 405 nm laser) While all samples were excited at the same excitation intensity the narrow-angle-Tamm-plasmon-perovskite shows strong enhancement by a factor of 2.6 in forward emission within a solid angle of ±15° perpendicular to the sample surface (calculations in Methods) which is crucial in applications that require forward emission we report strongly directional emission with our narrow-angle-Tamm-plasmon-perovskite structure demonstrating the versatility of this photonic platform a Normalised electroluminescence (EL) spectrum of reference PeLEDs and narrow-angle-Tamm-plasmon-driven PeLED Tamm plasmon resonance of the narrow-angle-Tamm-plasmon-driven PeLED shown with a reflectance measurement (black dashed line) b Current density–voltage–luminance performance of reference PeLED and narrow-angle-Tamm-plasmon-driven PeLED Inset: schematic of Tamm-plasmon-driven PeLED c Current efficiency–current density curve Inset: EQE–current density curve considering emission over all angles Angle-dependent EL spectrum of (d) reference PeLED (e) narrow-angle-Tamm-plasmon-driven PeLED and (f) wide-angle-Tamm-plasmon-driven PeLED collected across the PeLED surface macroscopically White dashed line: EL as a function of angle integrated from 490 nm to 540 nm (d Normalised EL integrated from 490 nm to 540 nm in (f) EL intensity of all configurations each normalised to the EL intensity of narrow-angle-Tamm-plasmon-driven PeLED (see colour bar) The red-shifted EL spectrum at small angles gradually blue-shifts with increasing collection angle due to shifting in Tamm plasmon resonance modes and the EL intensity peaks when Tamm plasmon modes resonate at the perovskite EL This result again demonstrates the versatility of the emission platform This work demonstrates the emitting material as the bottom layer of the photonic crystal at the metal-photonic-crystal interface in a planar Tamm plasmon system enhances directional photo-excited emission and can be integrated into an LED to show directional electroluminescence amplification the PeLED device stack and other photonic layers are all optically and/or electrically active layers in the Tamm plasmon structure in a monolithic fashion without use of further complicated optics the Tamm plasmon structure shows better spectral narrowing (sharper resonance) and higher normalised integrated electric field intensity within the perovskite layer for all blue (1.0 in Tamm plasmon 0.61 in metal-metal) and red (1.0 in Tamm plasmon the Tamm plasmon structure employs the exact device structure as reported with only the electrically inactive photonic crystal lying below ITO; practical replacement of ITO with metal in metal-metal cavities is challenging due to wettability and sensitivity issues when solution-processing the perovskite device layers on a metal and very few experimental demonstrations of working PeLEDs are reported in this architecture the Tamm plasmon structure has more degrees of freedom for design considerations - the photonic crystal can be more carefully designed to achieve a stronger electric field enhancement for a given LED device by tuning the electrically inactive photonic crystal for example by adding extra metal oxide layers again the electric field intensity values for the metal-metal cavities are near their upper limits due to limitations on device performance metal choice and absorption loss of the metal the metal in the Tamm plasmon structure is easier to fabricate compared with depositing DBR on top of perovskite films and can readily act as the electrode for the LED device by adding anti-reflective coating on the air/glass interface to improve outcoupling efficiency at wide angles as well as through investigation on the interaction between waveguiding modes and emission modes that can further enhance the emission of the Tamm-plasmon-driven PeLEDs we balanced the number of layers (complexity in manufacturing) with the final performance of our emitter and device We demonstrated Tamm-plasmon-driven PeLEDs with strong directional and enhanced emission The bottom photonic crystal layer at the metal-photonic-crystal interface in a Tamm plasmon system is replaced with an emitting quasi-2D halide perovskite layer to strongly confine the Tamm plasmon modes across the entire perovskite layer the narrow-angle-Tamm-plasmon-driven PeLED shows good directionality (angular FWHM of 36.6° compared to reference 143.9°) EL enhancement by 1.8 times at small angles and EL spectral narrowing from 22.4 nm to 12.1 nm The excellent adaptability of Tamm-plasmon-driven PeLEDs covering the visible spectrum enhanced directional emission (with narrow-angle Tamm plasmon resonance) tuneability of large angle directional emission (with wide-angle Tamm plasmon resonance) small thickness of active structure and relatively simple scalability of fabrication methods makes Tamm-plasmon-driven PeLEDs desirable The Tamm-plasmon-driven PeLEDs show potential in applications where angular control emission intensity and colour purity are crucial One-dimentional photonic crystal made of 3 pairs of alternating titanium dioxide (TiO2) and silicon dioxide (SiO2) were deposited on glass substrates in the Institute of Optoelectronics Thickness of each layer was TiO2: (70 ± 2) nm and SiO2: (90 ± 2) nm The photonic crystal were deposited in an e-beam evaporation system with a plasma source assistance (Syrus 710 Pro The base pressure of the system was 2 × 10−6 mbar TiO2 and SiO2 were deposited at 0.25 nm s−1 and 0.6 nm s−1 rate ITO electrodes were sputtered on glass substrates (for reference PeLEDs) and photonic crystal substrates (for Tamm-plasmon-driven PeLEDs) using a custom setup located in the Class 10,000 clean room in the Electrical Engineering Division The ITO electrodes were patterned using a metal mask The ITO sputtering utilised an In2O3/SnO2 90/10 wt% target with the pressure of 5 mTorr and power of 40 W The sputtering rate achieved was 3.7 nm minute−1 resulting in ITO conductivity of 1800 S cm−1 as measured by a 4-point-probe with an ITO thickness of 83 nm determined by AFM 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6 2,2’,2”-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi All chemicals were used without any further purification Glass substrates and glass/photonic crystal substrates were cleaned using detergent acetone and isopropanol under ultrasonication for 10 minutes each A solution of PVK (6 mg ml−1 in CB) was spin-coated onto the substrate at 4000 rpm for 30 s then immediately annealed at 100 °C for 10 min It is worth noting that other common hole injection layer such as Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) posses similar refractive indices making them compatible with such optical structures with concentration ranging from 0.13 M to 0.25 M were spin-coated at 6000 rpm for 90 s and immediately annealed at 70 °C for 5 min A 100 nm thick Ag film was subsequently thermally evaporated onto the perovskite film at a rate of 0.1 nm s−1 Glass/ITO substrates and glass/photonic crystal/ITO substrates were cleaned in detergent Poly-TPD (10 mg ml−1 in CB) and PVK (6 mg ml−1 in CB) is sequentially spin-coated onto the substrate at 4000 rpm for 30 s and immediately annealed at 100 °C for 10 min and 140 °C for 20 min The perovskite precursor of concentration 0.16 M (narrow-angle-Tamm-plasmon PeLED) and 0.25 M (wide-angle-Tamm-plasmon PeLED) was spin coated at 1000 rpm for 5 s and 4000 rpm for 55 seconds and then immediately annealed at 90 °C for 10 minutes LiQ (3 nm) and Ag (100 nm) were then sequentially thermal evaporated on the perovskite film the actual Tamm plasmon resonance wavelength at 0° should be ca The baseline measurement was done with a 100 nm thick evaporated silver mirror as a reference due to high reflectivity of our samples Reflectance measurement was cross-checked with the Agilent Cary7000 Universal Measurement Spectrometer using the Universal Measurement Accessory The sample is tilted at 6° and the detector at 12° to collect the specular reflectance without blocking the excitation lamp The baseline measurement is done at 100% transmittance without any reference thus eliminating any inaccuracy due to the reference defects Microscale reflectance of photonic crystal substrates was measured with hyperspectral microscope (Photon Etc A lamp light was focussed on the sample through a condenser from below the sample and was collected by the objective lens (Olympus MPLFLN20x with NA of 0.45) and measured by a CCD camera The measured reflectance of photonic crystal was calibrated with reflectance of a calibration mirror resistance and area of photodiode respectively \(r\) is the distance between photodiode and PeLED \theta \right)\) is the measured spectral radiant intensity at angle \(\theta\) \(R\left(\lambda \right)\) is the photodiode responsivity \({I}_{{{{{{\rm{PeLED}}}}}}}\) is the current across the PeLED Planck constant and speed of light respectively all 4 edges of the samples were masked with black tape to eliminate emission from the sample edge where \(\alpha\) is the solid angle of interest \({I}_{{{{{{{\rm{solid}}}}}}\; {{{{{\rm{angle}}}}}}}}\) is the PL or EL intensity \(S\left(\lambda,\theta \right)\) is the spectral radiant intensity Microscale PL was measured with hyperspectral microscope (Photon Etc The hyperspectral microscopy measurements were collected with objective lenses (Olympus MPLFLN) of 20x and NA of 0.45 (equivalent to collection angle of 26.7°) Time-resolved photoluminescence was measured at fluences between 1 and 370 nJ cm−2 pulse−1 with confocal microscope (PicoQuant MicroTime 200) The samples were excited with 405 nm pulsed laser (pulse width ~100 ps repetition rate 5 MHz) that was focussed with an 10x air objective lens Time-resolved photoluminescence at lower fluence between 0.01 and 5 nJ cm−2 pulse−1 were measured with photoluminescence spectrometer (Edinburgh Instruments FLS1000) repetition rate 2 MHz) was focussed on the samples at 45° and 60° and the emission was collected between 45° and 30° respectively at 1 nm bandwidth Time resolved emission scans were done by sweeping the emission collection wavelengths between 490-520 nm with 5 nm step Measurements are done with both unencapsulated and encapsulated samples in air and both shows similar results The data that support the findings of this study are openly available in Apollo—University of Cambridge Repository at https://doi.org/10.17863/CAM.109169 Details on the code that supports the findings of this study can be shared under request Potential long-term global environmental implications of efficient light-source technologies Comparative study of light emitting diode (LED) compact fluorescent (CF) and incandescent lamps Coherent (visible) light emission from Ga(As1−xPx) junctions Candela‐class high‐brightness InGaN/AlGaN double‐heterostructure blue‐light‐emitting diodes Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer Efficient green electroluminescent diodes based on poly (2-dimethyloctylsilyl-1,4-phenylenevinylene) efficient and stable perovskite light-emitting diodes Unveiling the additive-assisted oriented growth of perovskite crystallite for high performance light-emitting diodes Wedge waveguides and resonators for quantum plasmonics Localized and delocalized plasmons in metallic nanovoids Tuning localized plasmon cavities for optimized surface-enhanced Raman scattering Silver nanowires as surface plasmon resonators Extremely confined gap plasmon modes: when nonlocality matters General properties of slow-plasmon resonant nanostructures: nano-antennas and resonators Plasmonic metasurfaces for efficient phase control in reflection low-threshold monolithic perovskite thin-film vertical-cavity lasers Solution-processed low threshold vertical cavity surface emitting lasers from all-inorganic perovskite nanocrystals Strong exciton–photon coupling in hybrid inorganic–organic perovskite micro/nanowires Organic–inorganic hybrid perovskite nanowire laser arrays Room-temperature near-infrared high-q perovskite whispering-gallery planar nanolasers High photoluminescence efficiency and optically pumped lasing in solution-processed mixed halide perovskite semiconductors Losses in plasmonics: from mitigating energy dissipation to embracing loss-enabled functionalities Strong light confinement and optical force enhancement in phosphorene with acoustic plasmons Spectral narrowing and enhancement of directional emission of perovskite light emitting diode by microcavity Tamm plasmon-polaritons: Possible electromagnetic states at the interface of a metal and a dielectric Bragg mirror Tamm plasmon polaritons: slow and spatially compact light Flexible and adaptable light-emitting coatings for arbitrary metal surfaces based on optical tamm mode coupling Optical Tamm states enhanced broad-band absorption of organic solar cells Single photon source using confined Tamm plasmon modes Efficient light-emitting diodes from mixed-dimensional perovskites on a fluoride interface Highly efficient quasi-2D perovskite light-emitting diodes incorporating a TADF dendrimer as an exciton-retrieving additive Tunability and optimization of coupling efficiency in 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Hyperspy/Hyperspy v1.4.1. (Zenodo, 2018). https://doi.org/10.5281/zenodo.1469364 Download references The authors acknowledge the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (HYPERION Cambridge Royce facilities grant EP/P024947/1 Sir Henry Royce Institute—recurrent grant EP/R00661X/1 and the Engineering and Physical Sciences Research Council (EPSRC) (grant agreement Nos This work was co-financed by Military University of Technology under research project UGB 502-6700-23-759 acknowledges scholarship from St John’s College gratefully acknowledges a postdoctoral scholarship from the Max Planck Society and the Spanish Ministry of Universities for funding through a Beatriz Galindo Research fellowship BG20/00015 appreciates support from the Polish Ministry of Science and Higher Education within the Mobilnosc Plus program (grant no.1603/MOB/V/2017/0) and the National Science Centre (2022/47/D/ST5/03332) acknowledge funding from the Engineering and Physical Sciences Research Council (EPSRC) Nano Doctoral Training Centre (EP/L015978/1) acknowledges a George and Lilian Schiff Studentship the Engineering and Physical Sciences Research Council (EPSRC) studentship thanks the UK Engineering and Physical Sciences Research Council (EPSRC) grant EP/S023046/1 for the EPSRC Centre for Doctoral Training in Sensor Technologies for a Healthy and Sustainable Future S.Kahmann is grateful for funding from the German Academic Exchange Service (DAAD) (91793256) for a short-term research fellowship and from the Leverhulme Early Career Fellowship funded by the Leverhulme Trust (ECF-2022-593) and the Isaac Newton Trust (22.08(i)) acknowledges the support of the Spanish Ministry of Education Vocational Training and Sports through a Beca de Colaboración (Grant No acknowledges funding from the Leverhulme Early Career Fellowship (grant agreement No ECF-2019-224) funded by the Leverhulme Trust and the Isaac Newton Trust and from the Royal Academy of Engineering under the Research Fellowship programme acknowledge support from MICIU/AEI/10.13039/501100011033 and the European Union NextGenerationEU/PRTR through a PID2022-142525OA-I00 grant and a Ramón y Cajal Fellowship (RYC2021-034941-I) acknowledges the Royal Society and Tata Group (grant no We thank Youcheng Zhang (Cavendish laboratory University of Cambridge) for ITO conductivity checks the authors have applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising from this submission Department of Chemical Engineering and Biotechnology Max Planck Institute for Solid State Research Alberto Jiménez-Solano & Guadalupe Vega Krzysztof Gałkowski & Sebastian Maćkowski Faculty of Fundamental Problems of Technology Wroclaw University of Science and Technology Department of Materials Science and Metallurgy Departamento Física de la Materia Condensada Instituto de Ciencia de Materiales de Sevilla conceived and developed the Tamm-plasmon-driven PeLEDs modelled and optimised the Tamm-plasmon-driven PeLEDs with input from M.A fabricated and optimised the perovskite-based Tamm plasmon structure Z.Y.O fabricated and optimised the Tamm-plasmon-driven PeLEDs including ITO sputtering collected and analysed the HAADF-STEM and EDX data S.Kahmann and Z.Y.O collected and analysed the PL decay data Z.Y.O measured and analysed the PeLEDs performance S.Kar worked on solution-processed photonic crystal to study Tamm plasmon emission enhancement in early stage supervised the work undertaken in their laboratories and S.D.S wrote the manuscript with comments from all the authors The authors declare no competing interests Andreas Mischok and the other anonymous reviewer(s) for their contribution to the peer review of this work Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Download citation DOI: https://doi.org/10.1038/s41467-024-49838-1 Anyone you share the following link with will be able to read this content: a shareable link is not currently available for this article Sign up for the Nature Briefing newsletter — what matters in science « Back Metrics details Efficiently fabricating a cavity that can achieve strong interactions between terahertz waves and matter would allow researchers to exploit the intrinsic properties due to the long wavelength in the terahertz waveband Here we show a terahertz detector embedded in a Tamm cavity with a record Q value of 1017 and a bandwidth of only 469 MHz for direct detection The Tamm-cavity detector is formed by embedding a substrate with an Nb5N6 microbolometer detector between an Si/air distributed Bragg reflector (DBR) and a metal reflector The resonant frequency can be controlled by adjusting the thickness of the substrate layer The detector and DBR are fabricated separately and a large pixel-array detector can be realized by a very simple assembly process This versatile cavity structure can be used as a platform for preparing high-performance terahertz devices and opening up the study of the strong interactions between terahertz waves and matter These excellent properties are necessary for terahertz-band devices the functional components integrated with the DBR in the terahertz spectral range have rarely been reported in the literature The main difficulty is that the smallest planar features are of the order of λ/4nr ≈ 10 μm where nr is the refractive index of the dielectric Terahertz wavelengths are in the range 10 to 1000 μm so depositing thin films of an optical dielectric which is commonly used for optical devices which is necessary for the DBR structures used in terahertz devices the difficulties in depositing dielectric thin films and lateral etching are hard to address at the micro-scale in the terahertz band a detector or source integrated with a Tamm cavity in the terahertz band has not been reported experimentally and other high-performance functional devices The horizontal white line indicates the resonance characteristics of the hybrid Tamm cavity at dsubstrate = 510 μm and C correspond to the cases illustrated in (b The band gap of DBR is also marked with vertical white dashed lines on the graph i Spectral characteristics of the electric field intensity |Ed|2 in a hybrid Tamm cavity with different thicknesses of the substrates of the detector chips By using the electromagnetic wave transfer-matrix method (TMM) of multilayer media (Supplementary Note S1), the reflection spectrum of a DBR with three Si/air layers is calculated, as shown by the gray solid line in Fig. 1b The DBR reflects up to 100% in the band from 0.5 to 0.8 THz A spectrally wide stop band filter is realized just by three Si/air layers which benefits from the high refractive index contrast between HRFZ-Si and air The reduced period number also reduces fabrication and micro-assembly errors The thickness of the detector substrate in the cavity must also satisfy the following condition: This finding is verified by the following calculated results since the reflection coefficient is 0.6 and the electric field at the detector was not at a node of the standing wave the electric field intensity at the detector was 0 due to total reflection of the incident terahertz wave the reflection coefficient was only 0.2 and the electric field at the detector was at a node of a standing wave in the entire hybrid Tamm cavity so the enhancement factor was a maximum of up to 57 The electromagnetic field oscillated in the substrate layer and the energy was confined to the substrate layer and eventually absorbed by the detector greatly enhancing the response sensitivity of the detector This kind of hybrid Tamm cavity significantly enhances the interaction between terahertz waves and the sensor There is a significant difference in the electric field intensity at different locations so it is important to precisely control the thickness of each layer of the media during device preparation controlling the thickness at the micron level in deep silicon etching of MEMS is no longer a problem The resonant modes shift to lower frequencies as the substrate thickness increases which is consistent with the case with the substrate layer only localizes its energy within the DBR structure giving space for the detector substrate to excite FP cavity modes When designing this kind of hybrid Tamm cavity the target resonance points can first be calculated directly from the corresponding resonant modes of the detector chip only Then the DBR can be designed to excite Tamm modes to couple with these FP cavity modes enhancing the electric field at the detector without changing the resonant frequency points of the entire structure The detector chip and dielectric DBR are designed separately and then assembled together which is convenient for design and fabrication This all-silicon hybrid Tamm cavity can be used as a general platform for terahertz sources the ultimate solution for achieving strong interactions between terahertz electromagnetic waves and matter a 3D stereogram of the hybrid Tamm-cavity detector which consists of a DBR with three Si/air layers and a Nb5N6 microbolometer detector There is a metal reflector on the back of the detector chip b Side view of Si/air DBR layers assembled onto the detector chip after being bonded together with a photoresist c Package for a hybrid Tamm-cavity detector on a printed circuit board The multilayer DBR is obtained by stacking Si/air layer blocks the detector chips and the DBR chips are prepared separately and can be assembled or disassembled Fabricating this kind of hybrid Tamm-cavity structure is compatible with the fabrication of other terahertz functional devices it provides an excellent platform for enhancing the interactions between terahertz waves and matter there are many potential applications due to the strong electromagnetic coupling between the terahertz waves and the two-dimensional material The inset is a magnified view near the resonant mode at 0.476 THz The calculated Q values are extracted from reflection spectrum with nSi = 3.4147 and nSi = 3.4147–0.0008i a Measured optical responsivity of Tamm-cavity detectors with dsubstrate = 510 b Comparison of the measured and calculated resonant frequencies for dsubstrate from 510 to 420 μm The black dashed arrow indicates the blueshift and the cyan region is where the cavity modes overlap this is the pioneering report of a hybrid Tamm cavity terahertz detector and it achieves an ultra-high resonant Q value and narrow response bandwidth experimentally We demonstrated a terahertz detector integrated into a Tamm cavity positioned between a multilayer Si/air DBR and an Au reflector exhibits significantly enhanced interaction with terahertz signals within this hybrid Tamm cavity At the resonance wavelength of the Tamm mode the Au film and top DBR trap light effectively in the cavity resulting in local enhancement of electric field at the detector The detector achieves an exceptional Q (Q = 1017) with an extraordinarily narrow bandwidth (FWHM = 469 MHz) The Q of this hybrid structure surpasses that of a pure Tamm cavity and a Fabry-Perot cavity The ability to fine-tune the frequency for a narrow bandwidth by adjusting dsubstrate makes this approach highly promising for developing terahertz spectrometers achievable through straightforward MEMS processing and assembly without altering the device’s original resonant frequency offers a simplified design and implementation The versatility of this hybrid Tamm-cavity terahertz detector extends to enhancing the performance of various terahertz devices particularly in the realm of high-power sources its application holds promise for groundbreaking investigations into the strong coupling between 2D materials and terahertz waves TMM and electromagnetic simulation software (FDTD) are applied to calculate the reflectivity spectra associated with the profiles of the intensity enhancement of the electric field the permittivity of metal Au is described using the Drude model: \({\omega }_{P}/2\pi=2126.4\,{{{{{\rm{THz}}}}}}\) and \({n}_{M}=\sqrt{\varepsilon (\omega )}\) The authors declare that all relevant data are available in the paper and Supplementary Information or from the corresponding author on request Terahertz semiconductor-heterostructure laser Continuous-wave highly-efficient low-divergence terahertz wire lasers Widely tunable compact terahertz gas lasers “Graphene fieldeffect transistors as room-temperature terahertz detectors,” Terahertz sensor using photonic crystal cavity and resonant tunneling diodes Ultrafast terahertz detectors based on three-dimensional meta-atoms Resonant terahertz detection using graphene plasmons Tunnel field-effect transistors for sensitive terahertz detection A metamaterial solid-state terahertz phase modulator An ultrawide-bandwidth single-sideband modulator for terahertz frequencies THz-to-optical conversion in wireless communications using an ultra-broadband plasmonic modulator Terahertz integrated electronic and hybrid electronic–photonic systems Near-field out-of-plane coupling between terahertz photonic crystal waveguides Twenty years of terahertz imaging [Invited] Real-time terahertz imaging with a single-pixel detector Terahertz spectroscopy and imaging—modern techniques and applications Terahertz dynamics of electron–vibron coupling in single molecules with tunable electrostatic potential Terahertz gas phase spectroscopy using a high-finesse Fabry-Pérot cavity Wireless sub-THz communication system with high data rate Advances in terahertz communications accelerated by photonics Security and eavesdropping in terahertz wireless links Terahertz topological photonics for on-chip communication Perspective: terahertz science and technology Strong light–matter coupling in subwavelength metal-dielectric microcavities at terahertz frequencies Inducing an incipient terahertz finite plasmonic crystal in coupled two dimensional plasmonic cavities Tailoring terahertz near-field enhancement via two-dimensional plasmons Ultrastrong coupling of the cyclotron transition of a 2D electron gas to a THz metamaterial Resonant and nonresonant control over matter and light by intense terahertz transients Capture of a terahertz wave in a photonic-crystal slab Collective non-perturbative coupling of 2D electrons with high-quality-factor terahertz cavity photons Sub-diffractional cavity modes of terahertz hyperbolic phonon polaritons in tin oxide Electronic light–matter strong coupling in nanofluidic fabry–pérot cavities Condensation of semiconductor microcavity exciton polaritons Phase-locked coherent modes in a patterned metal–organic microcavity Dispersion engineering for vertical microcavities using subwavelength gratings Vacuum Rabi splitting with a single quantum dot in a photonic crystal nanocavity Ultrastrong coupling regimes of light–matter interaction Observation of ‘Tamm states’ in superlattices Tamm plasmon-polaritons: possible electromagnetic states at the interface of a metal and a dielectric Bragg mirror Hybrid optical Tamm states in a planar dielectric microcavity Observation of hybrid state of Tamm and surface plasmon-polaritons in one-dimensional photonic crystals Microcavity-integrated graphene photodetector Narrowband photodetection in the near-infrared with a plasmon-induced hot electron device Controlling Tamm plasmons for organic narrowband near-infrared photodetectors Organic photodiodes with an extended responsivity using ultrastrong light–matter coupling Tamm plasmon- and surface plasmon-coupled emission from hybrid plasmonic–photonic structures Narrowband thermal emission realized through the coupling of cavity and tamm plasmon resonances Room-temperature lasing in a low-loss tamm plasmon cavity Tuneable polaritonics at room temperature with strongly coupled Tamm plasmon Tamm plasmon sub-wavelength structuration for loss reduction and resonance tuning Tamm plasmon photonic crystals: from bandgap engineering to defect cavity Improvement of terahertz field effect transistor detectors by substrate thinning and radiation losses reduction Enhancement of responsivity for a transistor terahertz detector by a Fabry-Pérot resonance-cavity Analysis of the thickness dependence of metamaterial absorbers at terahertz frequencies Miniature MEMS: Novel key components toward terahertz reconfigurability Tuning a microcavity-coupled terahertz laser Broadband continuous single-mode tuning of a short-cavity quantum-cascade VECSEL One-way Tamm plasmon polaritons at the interface between magnetophotonic crystals and conducting metal oxides Strong longitudinal coupling of Tamm plasmon polaritons in graphene/DBR/Ag hybrid structure Gallium-nitride-based microcavity light emitting diodes with air-gap distributed Bragg reflectors High extraction efficiency light-emitting diodes based on embedded air-gap photonic-crystals Yasuhiko Room-temperature observation of trapped exciton-polariton emission in GaN/AlGaN microcavities with air-gap/III-Nitride distributed bragg reflectors Exciton–polaritons in van der Waals heterostructures embedded in tunable microcavities Room-temperature Tamm-plasmon exciton-polaritons with a WSe2 monolayer Two-dimensional semiconductors in the regime of strong light-matter coupling Engineering radiative coupling of excitons in 2D semiconductors An on-chip near-field terahertz probe and detector Terahertz time-domain spectroscopy characterization of the far-infrared absorption and index of refraction of high-resistivity Extremely low-loss terahertz waveguide based on silicon photonic-crystal slab Fabry–Pérot cavity-coupled microbolometer terahertz detector with a continuously tunable air spacer gap Investigation of antenna-coupled Nb5N6 microbolometer THz detector with substrate resonant cavity Download references We acknowledge support from the Innovation Program for Quantum Science and Technology (No the Fundamental Research Funds for the Central Universities the National Natural Science Foundation of China (Grant Nos the National Key R&D Program of China (Grant No the Excellent Youth Natural Science Foundation of Jiangsu Province (Grant No the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) the Key Lab of Optoelectronic Devices and System with Extreme Performance and Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves Research Institute of Superconductor Electronics (RISE) School of Electronic Science and Engineering Nanjing University of Aeronautics and Astronautics performed the reflectivity and transmittivity spectra calculations fabricated the devices and performed the measurements participated in discussions on this manuscript Thanks to Zhanzhang Mai for his assistance in revising the manuscript All authors discussed the results and commented on the manuscript Nature Communications thanks the anonymous reviewer(s) for their contribution to the peer review of this work Reprints and permissions Download citation DOI: https://doi.org/10.1038/s41467-024-49759-z Metrics details An Author Correction to this article was published on 25 March 2025 This article has been updated This paper presents a novel investigation of a magnetic sensor that employs Fano/Tamm resonance within the photonic band gap of a one-dimensional crystal structure The design incorporates a thin layer of gold (Au) alongside a periodic arrangement of Tantalum pentoxide (\(\:{\text{T}\text{a}}_{2}{\text{O}}_{5}\)) and Cesium iodide (\(\:\text{C}\text{s}\text{I}\)) in the configuration \(\:[\:\text{A}\text{u}/{\:\left(\right({\text{T}\text{a}}_{2}{\text{O}}_{5})/(\text{C}\text{s}\text{I}\left)\right)}^{\text{N}}]\) We utilized the transfer matrix method in conjunction with the Drude model to analyze the formation of Fano/Tamm states and the permittivity of the metallic layer These states can be manipulated based on the left-handed and right-handed circular polarization of electromagnetic waves we investigated how variations in magnetic field strength influence the position of Fano/Tamm resonance in the reflectivity spectrum of the interacting electromagnetic waves within a specific wavelength range of 60 μm to 140 μm The proposed sensor displays good performance investigated by calculating several parameters like it shows a maximum sensitivity of 57 nm/Tesla within a magnetic field strength of 20 to 140 Tesla positioning it as a promising candidate for various applications in magnetic field measurement and telecommunications particularly in the unique far-infrared region the defect layer is designed from an n-doped Si semiconductor material Their findings investigated that the defect mode can be shifted downwards the short wavelengths with the increase in the cyclotron frequency for RCP configuration the increase in the cyclotron frequency for LCP introduces a little shift in the position of the defect mode compared to RCP case towards the linger wavelengths their design could provide a relatively high sensitivity of 29 nm/Tesla for RCP case a highly doping concentration value is required toward achieving such sensitivity The detection procedure is mainly based on the emergence of the MOKE at a narrow spectral region corresponding to the surface plasmon-polaritons excitation the attained sensitivity is not exceedingly over 3 × 10–6 Oe their numerical results demonstrated the appearance of some dispersionless or flat bands which in turns makes the designed structure of a potential interest through many optical applications such as filters we have introduced a simple design based on the 1D PhCs to act as a highly sensitive magnetic field sensor The proposed design can be effective for a long range of the magnetic field values the considered structure comprises a thin layer of Au combined with a periodic arrangement of \(\:{\text{T}\text{a}}_{2}{\text{O}}_{5}\) and \(\:\text{C}\text{s}\text{I}\) through the optimum design \(\:[\:\text{A}\text{u}/{\:\left(\right({\text{T}\text{a}}_{2}{\text{O}}_{5})/(\text{C}\text{s}\text{I}\left)\right)}^{\text{N}}]\) the applied magnetic field is introduced based on Faraday configuration the designed structure demonstrates the coupling between Fano and Tamm plasmon resonance modes which represents the mainstay of our study This coupled mode provides a highly sensitive response regarding the applied magnetic field copared to some of the previous studies Au metallic layer receives some variations on its permittivity with the presence of the applied magnetic field as being discussed in the upcoming section the shift in the spectral position of the coupled Fano/Tamm mode is expected this is the first time in which the excitation of the coupled Fano/Tamm resonance could be introduced to act as a sensor for the magnetic field a detailed optimization process have been carried out to adopt the best performance of the designed sensor our designed structure was initially introduced as [A(BC)N] where the symbol A represents the metallic material as the first layer and (BC) denotes the periodic structure of the PhC with N representing the number of periods our numerical finding demonstrates firstly the emergence of the coupled Fano/Tamm resonant mode based on some organic and nonorganic materials in the design of our PhC structure this sensor demonstrates a brilliant response for small and wide ranges of an applied magnetic field; it can be fruitful in a broad range of applications in optical communication systems and scanning applicants Our approach relies on the principles of the transfer matrix method and the Drude model Numerical results show that the external magnetic field has a significant impact on the permittivity of the metal layer within the periodic photonic crystal at the resonant peak the position and intensity of the coupled Tamm/Fano resonance mode are greatly influenced by the strength of the applied magnetic field this design serves as an excellent candidate for magnetic applications and medical biosensors as well as for optical communication systems particularly in the infrared range of the spectrum This paper is organized as follows: In Sect we discuss the fundamental equations used in our analysis Section 3 presents the numerical results and discussions on the reflectance characteristics of the 1D photonic crystals achieved through a thorough optimization of all sensor parameters to determine the optimal design for the photonic crystal magnetic field sensor 4 summarizes the conclusions drawn from this study The schematic diagram depicts a multi-layer photonic crystal structure composed of \(\:{\text{T}\text{a}}_{2}{\text{O}}_{5}\:\text{a}\text{n}\text{d}\:\text{C}\text{s}\text{I}\) with a thin gold film covering the front face and a silicon substrate underneath The entire photonic crystal design is subjected to an applied magnetic field Whereas the resultant response of the EMWs between the boundaries (x0 and x1) of a certain layer \(\:i\) with thickness \(\:{d}_{i}={x}_{1}-{x}_{0}\) \(\:{\varsigma\:}_{0}\) and \(\:{\varsigma\:}_{s}\) stand for air and substrate Here,\(\:{{\upomega\:}}_{\text{m}}\) and\(\:\:{\rm\:Y}\) are denoted as the plasma and damping frequencies these constants for Au have the values 13.71013 × 1015 and 40.49009 × 1012 in rad\ sec as indicated in Table 1 \(\:{\upomega\:}\) is the angular frequency of the incident radiation (\(\:{\upomega\:}=\raisebox{1ex}{$2{\uppi\:}\text{c}$}\!\left/\:\!\raisebox{-1ex}{${\uplambda\:}$}\right.)\) the refractive index of Au could be computed from: \(\:{m}_{e}\) depicts to the electron mass the permittivity of the metallic layer due to the effect of the external magnetic field for both right and left circularly polarized light categories respectively could be listed as: We aim to determine the optimal design for the photonic structure based on the materials used, the type of metal on the top surface, the thickness of each layer, the number of periods, and the angle of incidence, as well. In particular, the selection of these parameters will significantly impact the performance of the sensor. The reflection spectrum of the initial PhC structure of [Au/(SrF₂/PMP)5] as a function of the wavelength at incident angle equals 0° we have started our optimization process towards the best performance of our sensing tool we have considered the case of the normal incidence for the interacting EMWs The first imposed design for the optimization process incorporates two layers: SrF₂ and PMP All of parameters and values are kept as the same imposed values in the last subsection The proposed structure is structured as [Metal / (SrF2/PMP)5 This design shows the emergence of the coupled Tamm/Fano resonance mode as shown in Fig. 2 we have optimized all of the materials used besides their thicknesses as follows The sensitivity of the PhC magnetic field sensor [Metal / (SrF2/PMP)5] versus different metals such as Ag The sensitivity of the designed 1D PhC magnetic field sensor based on the substitution of SrF2 layer in each PhC’s unit cells different types of the materials such as and \(\:{\text{T}\text{a}}_{2}{\text{O}}_{5}\) i.e. The sensitivity of the designed 1D PhC magnetic field sensor based on the substitution of PMP layer in each PhC’s unit cells different types of the materials such as The sensitivity of the proposed sensor [Au / (Ta2O5/CSI)5] against the thickness of the metallic layer \(\:{\text{d}}_{\text{m}}\) The variation of the sensitivity of the sensor as a function of changing the thickness of Ta2O5 layers Sensitivity of magnetic field sensor based on alternating in CsI layers thickness of PhC design [Au / (Ta2O5/CSI)5] The sensitivity of magnetic sensor versus the alternative number of periods between 3 and 12 for the PhC structure [Au / (Ta2O5/CSI) N ] Variation of the sensor sensitivity as a function of the incident angle The light reflection spectrum of [Au/(Ta2O5/CSI)5] sensor as a function of the wavelength at different magnetic field values and incident angle of \(\:{30}^{^\circ\:}\) (a–c) manifest the performance parameters such as Sensitivity and Uncertainty of sensor under an applied specific range of magnetic field A fitting graph of changing the Fano/Tamm resonant position with the magnitude of the magnetic field we believe that our designed magnetic field sensor could be of a significant interest compared to its counterparts due to its relatively high sensitivity and design simplicity as well we have introduced a magnetic field sensor based on a 1D photonic structure in which a thin metallic layer is deposited on the top surface of a 1D PhCs the inclusion of the metallic layer leads to the emergence of a coupled Fano/Tamm resonant mode the shift of this resonant mode represents the mainstay of the detection procedure our theoretical methodology towards the investigation of the numerical findings is mainly based on the well-known TMM The numerical findings demonstrate that an optimal structure of,\(\:[\:\text{A}\text{u}/{\:\left(\right({\text{T}\text{a}}_{2}{\text{O}}_{5})/(\text{C}\text{s}\text{I}\left)\right)}^{5}]\) provides a relatively high sensitivity of 57 nm/Tesla this value was achieved at some optimal geometrical and structural parameters such a layers’ thicknesses incident angle and periodicity number as well we believe that our designed sensor could provide valuable insights for magnetic field detection Requests should be addressed to corresponding author on a reasonable request A Correction to this paper has been published: https://doi.org/10.1038/s41598-025-95034-6 Effects of configuration interaction on intensities and phase shifts Tunable Fano resonance in a one-dimensional photonic crystal containing a Weyl Semimetal Plasmonic sensing and modulation based on Fano resonances Fano resonance in a MIM waveguide with double symmetric rectangular stubs and its sensing characteristics Ultrasensitive terahertz sensing with high-Q Fano resonances in metasurfaces 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contained an error in the Acknowledgements section It now reads: “The authors acknowledge Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2025R400) Download citation DOI: https://doi.org/10.1038/s41598-025-85747-z Sorry, a shareable link is not currently available for this article. Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily. One of the most acclaimed sandwich joints in town called it quits over the weekend. Nomad, which shares a building in Dogtown with Tamm Avenue Bar (1227 Tamm) announced the closing today on social media Chef-owner Tommy Andrew’s post reads I want to make it clear that nomad was a successful restaurant We are not closing because of anything financial.” Andrew, whose impressive chef’s resume includes Monarch “It’s been a great five years serving Dogtown in St I’ve been here grinding away since July 2019 with plans to open my own brick and mortar It’s clear that’s not the case in my current situation I’m not a young man anymore and we need a bigger kitchen.” When Nomad opened inside Tamm Avenue Bar five years ago Andrew (who also answers to “Tommy Salami”) proceeded to crank out some of the best sandwiches in St The pastrami sandwich (which he almost called “Tommy Salami’s Pastrami”) Burger aficionados craved the Double Deuce (a burger-pastrami combo) and the double-pork patty Dumpster Fire Andrew was soon producing significant volume from a closet-size kitchen tells SLM that the endgame was never to stay in Tamm Avenue Bar permanently The concept opened 21 days before the pandemic hit; it was an immediate success and he managed to pay off his debt in two years “I don’t know that there’s anyone else who can say that,” he says “I made more money than I ever have and worked harder than I ever have to get to the next chapter and felt the time was right to do that,” he says of his partnership at Tamm “[Tamm] was taking on more of a sports bar/club atmosphere and was getting busier and busier It got to the point that I couldn’t keep up with the volume There’s a certain level of customer experience that I want to provide and we were trying to feed 500 people a day.”  Andrew’s goal is to eventually find a turnkey operation (2000-square-feet or larger) where he has full control and the ability to run a full table service operation He recently took a trip with his fiancée to a Michigan beach (his first vacation in two years) and plans to take the several months off before seriously searching for a new home “I feel like I was letting a lot of people down,  Andrew’s social media post concluded, “Thank you to all the guest, @Nomad staff and @tammavebar y’all will always be family. I’m taking this time to spend with my family and focus on my mental and physical health.”  St. Louis Magazine is the smart, sophisticated guide to your city. Our award-winning content brings readers revealing profiles, discerning dining and cultural guides, in-depth features, informed commentary, and authoritative best-of lists. Start your mornings with a fresh take on the day’s top local news, with the St. Louis Daily, from Sarah Fenske and Ryan Krull. Copyright 2025 SLM Media Group. All rights reserved. Your Ads Privacy ChoicesIMDb, an Amazon company© 1990-2025 by IMDb.com, Inc. Volume 3 - 2021 | https://doi.org/10.3389/fnano.2021.638442 Thin films of noble metals with thickness smaller than the wavelength of light constitute one of the most investigated structures in plasmonics The fact that surface plasmon modes can be excited in these films by different ways and the simplicity of fabrication offer ideal conditions for applications in nanophotonics The generation of optical modes in coupled Fabry-Pérot planar cavities and their migration to hyperbolic metamaterials is investigated Coupled Fabry-Pérot cavities behave as simple coupled resonators When the intra-cavity media have different refractive indices in two or more coupled cavities resonance anti-crossings arise The application of this kind of strong coupling in sensing is foreseen Beyond the cavity modes excited by propagating waves also long range plasmonic guided modes can be excited using emitters or evanescent waves A periodic structure made by multiple plasmonic films and dielectrica supports bulk plasmons of large propagation constant and increasing field amplitude The optical response of these structures approaches that of the hyperbolic metamaterial predicted by the effective medium theory Light can propagate with full transmission in a structure made of a photonic crystal based on quarter wavelength layers and a second photonic crystal with an overlapping forbidden band but presenting a non-trivial topological phase achieved by band inversion This is due to excitation of optical Tamm states at the boundary between both crystals The extension to multiple optical Tamm states using dielectric and plasmonic materials and the symmetries of the edge states is investigated Despite the intensive research already done the motivation to study some of the optical properties of layered media and the wide range of applications of the plasmon resonances did not fade Layered dielectric media play a very important role in optics The insertion of plasmonic films into dielectric layered media not only adds mathematical complexity and increases the degrees of freedom for optical manipulation but allows to confine and propagate optical fields to a level never achieved by photonic media This degree of optical confinement is at the base of the modern applications of classical and quantum physics In this article several less investigated properties of surface plasmon modes in layered media are addressed The main features of the near-fields and propagation properties are compared among different structures small changes in the layer thickness leads to completely distinct optical regimes but some characteristics of the optical modes are preserved This includes the application of planar cavity Fabry-Pérot resonators to generate strong coupling The analysis of coupled surface plasmon modes in finite sized metal-dielectric stacks to obtain hyperbolic metamaterials and optical Tamm states follows To my knowledge the application of Fabry-Pérot cavities to demonstrate classical strong coupling between light modes and its potential on sensing applications was not yet explored. The strong coupling between small plasmonic cavities (Ameling and Giessen, 2012) and beyond the light line (evanescent waves) has been investigated (Menghrajani and Barnes, 2020) The investigation of hyperbolic metamaterials based on periodic metal-dielectric bilayers is often based on the effective medium theory and on the Kronig-Penney model In this article the plasmonic modes excited in finite layered media are analyzed without approximation models The plasmonic modes exhibit rich symmetry properties not possible to investigate using the theoretical models based on infinite layered media the investigation of the optical Tamm states closely related to photonic topological insulators in one dimension has been limited to a single interface In this article the effects arising for double edge states are discussed Samples were fabricated for the experimental characterization of Fabry-Pérot coupled optical cavities and the experimental demonstration of strong coupling between light modes Samples for experimental verification of the coupled optical Tamm states were also fabricated and characterized The article is structured in the following way A short description of the simulation methods used is given The theory of plasmon modes in single and double metal-dielectric interfaces in thin films is summarized In more complex structures made of multiple layers where the solutions of Maxwell's equations hardly can be found analytically the transfer matrix method and the scattering matrix method are used to obtain the mode dispersion and the field profiles The fabrication techniques and the optical characterization is presented in the following section Three examples of layered structures and the application of the corresponding surface plasmon modes are discussed the properties of Fabry-Pérot modes in planar cavities based on silver mirrors and their application in the generation of strong coupling between cavities is discussed These resonances are due to cavity modes and not to guided plasmonic modes These structures offer a significant advantage in sensing over the classical plasmonic resonators because they provide optical resonances with a quality factor or the order of Q ~ 100 and simultaneously the silver surface can be isolated from an analyte When several identical Fabry-Pérot resonators are stacked together and the layer dimensions become much smaller than the wavelength another effect arises Fabry-Pérot resonances cease to exist but a new family of guided plasmon modes arises: bulk plasmons with large k-vectors These modes are representative of the hyperbolic dispersion arising for an infinite number of bilayers To understand this uniaxial dispersion the effective medium theory based on the homogenization of the dielectric function in two orthogonal directions has been used this theory cannot be used to investigate single plasmon modes and their propagation constants Finite length plasmonic-dielectric structures have a number of modes identical to the number of interfaces and their properties can be analized using the transfer matrix method The third class of structures is based on the optical Tamm states arising in coupled one-dimensional photonic crystals with a non-trivial Zak phase and between a photonic crystal and plasmonic film The discussion addresses cases beyond the single interface In this section the properties of plasmonic modes in one and two interfaces are summarized The application of the transfer matrix method and the scattering matrix method in multiple layers in order to determine the dispersion relation is presented A p-polarized plane electromagnetic shinnes on a metal film, of thickness d ≫ λ and parallel to the XY-plane, with complex dielectric function ϵm(ω) = ϵm,r + ϵm,i. The upper medium has permittivity ϵ1. The magnetic field near the interface is given by 1 where β = kr + iki and electric field components are The function f(z) is an exponential decaying function with form The dispersion relation is obtained from the continuity of tangential components of the electric field there is a surface wave propagating at the interface metal-dielectric the k-vector of the incoming light wave k0n1 cos θ never equals kr independently of the angle of incidence θ any plane wave cannot excite the surface plasmons at a single interface where the electric field oscillates in the XY-plane never excites surface plasmon in flat layers When the thickness of the metal film d decreases to values compared to its skin depth and the film is sandwiched between two dielectric media of constants ϵ1 and ϵ2 there are two metal-dielectric interfaces whose surface modes interact where αj=β2-k02ϵj, with j = 1, 2, 3. When ϵ1 = ϵ3 the equation above has two solutions. One correspondends to an antisymmetric electric field distribution on both sides of the metal film (Smith et al., 2008) The other has a symmetric electric field distribution Only for p-polarized light these modes can be excited For s-polarized light there are no solutions A large imaginary part of β is reflected in a short propagation length. Long propagation length is desired in applications and plasmonic waveguides and long range optical interactions (Berini et al., 2007) The calculation of the reflectance, transmittance, absorbance, and fields in the layered structure are based on the transfer matrix method (Yeh, 2005) A layered medium is made of N optical layers each with refractive index nj and thickness dj (i = 1 surrounded by semi-infinite media of refractive index n0 and ns The layered medium is illuminated with a plane electromagnetic wave of p-polarization (TM) Using the amplitudes Aj and Bj in each layer associated with the forward and the backward propagation waves we can use the transfer-matrix to obtain the amplitudes of the fields in each layer The field (either the electric field component Ey for the s-polarization or the Hy magnetic field component for the p-polarization) in the layer j defined by the interval between zj and zj+1 is described by a sum of plane waves traveling in the opposite direction of the z-axis The relationship between amplitudes for two consecutive layers j and j + 1 reads By iterating for the full layered structure From the matrix M we can obtain the reflectance and transmittance using The S-matrix relates the forward and backward field amplitudes in the layer l and in the layer l′ in an entirely different way The outgoing field amplitudes are determined from the incoming field amplitudes by The elements of the M-matrix and the S-matrix in an arbitrary layer p are related by Li (1996) In the calculations done in this article two matrix-based codes were used. (a) An adapted version of the Python TMM code based on the T-matrix calculation (Byrnes, 2019) was used for the reflectance, transmittance and fields in the layered structure. (b) An adapted version on the MATLAB Moosh code was used to obtain the guided modes and field profiles of plasmonic-dielectric layered structures (Defrance et al., 2016) The fields inside the structure and the reflectance and transmittance spectra of the planar photonic crystals used in the generation of optical Tamm states were verified using COMSOL Multiphysics All samples were fabricated by successive electron-beam evaporations of metal and dielectrics on glass cover slide substrates The vacuum pressure before the evaporation was 10−6 mbar Samples fabricated for layered hyperbolic metamaterials were based on coatings of Al2O3 and silver Aluminum oxide has a major advantage over silicon dioxide when some of the layers are of noble metals It offers much better inter-layer adhesion which prevents cracking and detachment from the substrate The effective refractive index of each coating depends on the evaporation conditions and small deviations from those values in the literature are expected The samples fabricated were inspected by optical microscope For samples placed in the vertical direction to the evaporation source the film thickness is in good agreement with the measured value by the quartz balance a comparison was made by measuring the topography of a film stripe by AFM (atomic force microscopy) In substrates placed off the vertical direction the film thickness decreases with increasing angle between evaporation source and substrate measured from the vertical Further experimental characterization of the dielectric films The profile of multilayers can be imaged by scanning electron microscopy In order to achieve an optical wide bandgap in a planar photonic crystal based on two dielectric media with a lower refractive index nl and a higher refractive index nh a large difference in the refractive index of the both materials is required (Yeh, 2005) a natural choice is to employ TiO2 and MgF2 the film growth conditions required for a good adhesion and constant stoichiometry could not be fulfilled with the evaporation system available The substrates could not be heated and the temperature controlled though this is a recommendation of the materials suppliers Better films quality and adhesion properties was achieved using the pair ZrO2 and SiO2 multiple PCs deposited in two or more steps lead to widespread cracking The cracking is absent in a single PC up to 14 bilayers but becomes common if the number of layers duplicate The best results were achieved using Ta2O5 and SiO2 despite to modest conditions of the evaporation the recommended partial pressure of O2 could not be used and no ion assisted deposition was employed in the electron-beam evaporation process the reflectance experiments show that these films can be prepared to obtain optical Tamm states and verify the theoretical predictions All the materials referred above were selected because of their optical properties in the visible and NIR spectral range For longer wavelengths other materials of larger refractive index and low absorption can be used The reflectance of the samples was measured using a WITec SNOM/Confocal microscope equipped with an Zeiss Achrostigmat (5x NA = 0.12) for illumination and light collection A halogen white light source was used for excitation and an Avantes AvaSpec-ULS-TEC spectrometer was used for the spectral characterization The angle-resolved reflectance of the coupled Fabry-Pérot cavities presenting strong coupling were characterized using a collimated halogen light source (Ocean Optics HL-2000-FHSA) and an optical spectrometer (Ocean Optics S2000) The samples were mounted in a rotating stage Measurements of the reflectance were done for angles between 10° and 80° to the vertical in steps of 2° Layers of a metal separated by a dielectric medium of refractive index n and thickness d ≥ λ/2 form a Fabry-Pérot (FP) resonator Despite the penetration of field into the metal the cavity length can be approximated to the half wavelength In a stack formed by 3 metal layers and two intercalated dielectric layers of the same thickness two resonances in the reflectance and transmittance spctrum arise with a wavelength separation Δλ dependent on the thickness of the central metal layer a stack of two Fabry-Pérot cavities coupled by a middle metal layer corresponds to the optical analog of the classical coupled oscillators When the thickness of last metal layer largely exceeds the light penetration depth (i.e. almost total absorption is reached at the resonances of the single or double Fabry-Pérot resonators The calculated and experimental Q-factor of the cavity resonances can reach values above 100 The half-wavelength resonance is the first mode Higher modes are excited for shorter wavelengths The resonances at vertical incidence show very low sensitivity to changes in the refractive index of the first and last media for an angle of incidence >30 ° the resonances start to have large sensitivity to a variation of the refractive index in the first medium The classical analog of the strong coupling can occur not only in cavity modes excited by propagating waves, rather between surface plasmons modes, when β > k0 (Ameling and Giessen, 2012; Menghrajani and Barnes, 2020) The only requirement is the design of dispersion curves that would cross The results presented is this article are however restricted to the case of excitation by propagating waves The advantage of the strong coupling in coupled cavities using two different intra-cavity dielectrics Al2O3 with nh ~ 1.76 and MgF2 with nl ~ 1.38 is the large sensitivity to the refractive index of the first medium for angles of incidence close to the angle where anti-crossing in the dispersion is reached Silver films offer the best plasmonic properties, namely long propagation length of surface plasmons, low optical absorption, but are not adequate in biological sensing applications because of the chemical activity of silver. Sensing variations of the refractive index of a dielectric medium in the Kretschmanm-Raether setup, requires either a solution, an inert solid material, or any material of low chemical activity in contact with the silver, or gold film (Homola, 2008) Coupled Fabry-Pérot cavities presenting anti-crossing can be sandwiched by protective layers of Al2O3 and be used in refractive index sensing Figure 1A presents the dispersion of two coupled Fabry-Pérot cavities using silver films and Al2O3 as a intra-cavity medium. In Figure 1B are presented experimental spectra obtained at normal incidence for single and coupled cavities indicating moderate Q-factors and narrow resonance bandwidth in the visible (A) Reflectance of an IMIMIMI stack integrating two identical Fabry-Pérot cavities made of silver and aluminum oxide layers The substrate is silicon dioxide and the first medium is air (B) Experimental reflectance at normal illumination of two samples with single and double Fabry-Pérot cavities In Figure 2 are presented calculated and experimental results of the dispersion for two an three coupled cavities. In the calculated results (Figures 2A,B) the first and the last medium are the same. In the experimental results the illumination if from air and the substrate is glass. In the three coupled cavities there are two anti-crossings. The effect of the variation of the refrative index of the first medium is illustrated in Figure 3 For angles above 30° the lower curve deflects rapidly with an increase of the refractive index n1 Strong coupling in coupled planar Fabry-Pérot cavities (A) Reflectance for two coupled cavities with different intra-cavity dielectric materials: aluminum oxide and magnesium fluoride The strength of the coupling depends on the thickness of the inter-cavity silver layer The tuning parameter to achieve the classical strong coupling is the angle on incidence of a plane wave The dispersion also depends on refractive index of the first and the last medium at vertical incidence the position of the resonances is almost unperturbed by changing the refractive index of the first medium (C) Experimental reflectance for two cavities with p-polarized light illumination from air (D) Experimental reflectance for three cavities in symmetric arrangement where the middle cavity has the lower refractive index (MgF2) Reflectance of coupled planar cavities presenting strong coupling with dependence on the refractive index of the first medium At vertical incidence (θ = 0) the reflectance is independent of the refractive index of the first medium but for angles larger then 30° fast deflection of the lower curve arises The cavity modes discussed in the previous section are excited by propagating waves. Evanescent wave modes also exist for coupled Fabry-Pérot cavities. They propagate along any direction in the plane of the layers with constant β. For single and double metals layers forming IMI and IMIMI structures analytic and closed form solutions of the dispersion relation of surface plasmons exist (Economou, 1969; Raether, 1988) In structures with more layers of dispersive materials the roots of the complex equations are difficult to obtain and other semi-analytical methods are more convenient The dispersion of plasmonic modes is achieved by evaluation of the integrand functions of the power loss of a harmonic oscillating dipole very close to a metal surface the decay rate of a dipole in a homogeneous medium of dielectric permittivity ϵ1 is given by γ = P/(ℏω) Near an interface separating the medium where the dipole is located from other semi-infinite medium the power loss is dependent on the reflection coefficients of these media and the distance to the dipole There is a radiating contribution and a non-radiating contribution to the decay rate depending on the k-vector of the radiating field The radiating contribution to the power spectrum is given by where k1 is the k-vector of the medium where the dipole is located The non-radiating contribution includes guided modes namely surface plasmon modes associated with non-propagating k-vectors larger than k1 These modes can be calculated based on the Fresnel reflection coefficients from the boundary for the s- and p-polarization The quantum efficiency of the radiation is given by the ratio The decay rate can be decomposed into a parallel (in-plane) and a perpendicular (out-of-plane) term because they rely on different contributions of the Fresnel reflection coefficients for p- and s-polarization The density of power loss of an isotropic dipole as it is expected from a dye molecule embedded in a dielectric transparent medium For a dipole near in a medium of dielectric permittivity ϵ1 at a distance d to a second medium of permittivity ϵ2 (or an arbitrary layered medium) the decay rate for the parallel and perpendicular components is given by Ford and Weber (1984) and Barnes (1998) u = k1/k0 and li=-i(ϵj/ϵ1-u2)1/2 with j = 1 in order to obtain the dispersion relation these integrals have not to be evaluated If the second medium is substituted by a layered medium of dielectric and plasmonic layers the corresponding reflection coefficients are obtained from the transfer matrix calculation The second method to obtain the dispersion relation relies on the scattering matrix calculation. It is a semi-analytical calculation method. The main advantage of the scattering matrix comparing to the transfer matrix is its numerical stability, in particular when absorbing media are involved. The dispersion is found by solving the roots of the following equation, by the steepest descent method (Defrance et al., 2016) and f is determined using the scattering matrix for the layered structure. The MATLAB library MOOSH was employed for this purpose (Defrance et al., 2016) The plasmon modes of large k-vector propagate inside the layered medium and are therefore called volume plasmons The dark regions correspond to the plasmon guided modes Plasmon modes have always a k-vector larger then k1 = k0n1 the propagation constant of the first medium The bright lines in the left region denote the cavity modes for p-polarized light Figure 5. Dispersion relation of the SPP modes supported in a pair of silver films separated by a dielectric layer of aluminum oxide. The materials and geometrical parameters are the same of the Figure 4 The bright regions correspond to the highest density of power loss of an isotropic dipole located at 5 nm away the first silver surface The less pronounced curves for effective index kx/k0 < 1.0 Samples were fabricated using bilayers of Al2O3 and silver with thickness d ≪ λ The experimental investigation of these samples namely the properties of propagating plasmons and the fluorescence lifetime of emitters near the first silver layer can provide more information for their potential application in quantum optics experiments The homogenization of the EMT requires a unit cell size much smaller than the wavelength of light in the frequency range considered The resulting dielectric function is calculated based on geometrical parameters and on the dielectric functions of the constituent materials and their lengths along the symmetry axes of the periodic structure For a layered medium made of binary layers of materials with dielectric functions ϵ1(ω) and ϵ2(ω) and thicknesses d1 and d2 the EMT dielectric function results into two components: one for any axis parallel to the layers and one for the axis perpendicular to the layers Assuming that the layers are parallel to XY-plane then ϵxx = ϵyy = ϵ∥ and ϵzz = ϵ⊥ and using k0 = ω/c the in-plane and the out-of-plane dielectric functions read The corresponding dispersion equation takes the form (Guo et al., 2020) The first term corresponds to the ordinary TE wave and the corresponding isofrequency surfaces (ω = const.) are spherical The second term corresponds to the extraordinary TM waves When ϵ∥ > 0 and ϵ⊥ < 0 both modes exist and the second term leads to a dispersion whose isofrequency have double sheet hyperboloid shape (Type I) For ϵ∥ < 0 and ϵ⊥ > 0 only the TM waves can propagate and isofrequency surfaces have single sheet hyperboloid shape (Type II) Type II hyperboloids have negative Gaussian curvature everywhere whereas Type I hyperboloids have positive Gaussian curvature Array of rods of dielectric function ϵm(ω) embedded in a isotropic medium of dielectric function ϵd form other example of hyperbolic metamaterial, where the EMT homogenization can also be applied. Rods of diameter r and lattice constant L arranged in a squared lattice and oriented along the z-axis have the following EMT dielectric functions (Shekhar et al., 2014): is defined as the ratio between the area of the cross-section of the rods a and the area of the unit cell of the lattice A The effective dielectric function components of a hyperbolic material made of an infinite number of silver (10 nm thickness) and Al2O3 (20 nm) layers are presented in Figure 6 The parallel and perpendicular components were calculated using the effective medium theory equations Figure 6. Dielectric functions of a plasmonic-dielectric layered medium calculated using the effective medium theory. Each bilayer is composed of silver (10 nm) and aluminum oxide (20 nm). The permittivity of silver was obtained from the optical constants from Johnson and Christy (1972) The spectral regions labeled with Type I and Type II are the regions where the real part of perpendicular and parallel parts of the dielectric function become negative The wavelengths at which the profiles were calculated are in the range of the Type II hyperbolic modes branch Profiles of the field component Hy for λ = 633 nm along the stack of 5 silver layers of 30 nm thickness separated by aluminum oxide layers of 50 nm thickness The first two lines correspond to the Hy with symmetric and antisymmetric profile The two modes have maximum amplitude at the external boundaries the bulk modes have increasing amplitudes with increasing kr The vertical black lines indicate the boundaries between layers Profiles of the field component Hy for λ = 800 nm along the stack of 6 silver layers of 30 nm thickness The symmetry center is in the central dielectric layer Due to the large field strength inside some layers and the well-separated propagation constants of the volume modes it would be of high relevance the selective excitation of single plasmon modes It is also noteworthy that an early discovery of electron states in truncated crystals, the edge states, are now investigated from the perspective of topological insulators, giving them a much large degree of generality. The impact of topological materials and topological insulators has achieved a large scale attraction, from effects arising in classical waves to states of quantum matter (Hasan and Kane, 2010; Haldane, 2017) Topology properties are more general than geometry properties as symmetry A topological space preserves its properties by a continuous deformation whereas an arbitrary space deformation often means a break of symmetry properties of physical systems with topological invariance are robust against small deformations and defects The electron edges states of one-dimensional atom lattices have an analog in photonics substituting the periodic potential by a layered structure with periodic refractive index Despite the fact that the edge states of photonic crystals are only analogs of the edge electronic states discovered by Tamm for historical reasons it is reasonable the call edge states arising in truncated photonic crystals optical Tamm states (OTS) Presently many publications are dedicated to the study of edge states and the associated topological properties in two- and three-dimensional photonic crystals and in arrays of plasmonic particles (Wang et al., 2008, 2016; van Miert et al., 2016; Proctor et al., 2020) In this article only one-dimensional edge states and their properties are discussed In a photonic crystal of indefinite length the bulk Bloch modes (bands) for illumination at vertical incidence (θ = 0) are found from the dispersion relation of the layered medium, which reads (Yeh, 2005) with k1 = (ω/c)n1 and k2 = (ω/c)n2. The thicknesses of the layers are d1 = a and d2 = b and the refractive indices n1 and n2, respectively. KB is the Bloch k-vector and Λ = a + b. A similar equation arises in the dispersion of the Kronig-Penney model of electrons in solids (Kronig and Penney, 1931) Tamm to find the edge states of electrons in a one-dimensional lattice but substituting the propagation constants k1 and k2 by constants related to the periodic potential function Forbidden gaps in the energy occur for R[KB] = nπ/Λ, with n = 1, 2, … . In the forbidden bands KBΛ = π ± ix, where x is a function of the refractive indices n1 and n2 (Yeh, 2005) Bandgaps centered in the wavelength λ = λg arise when the following condition is verified I should be noted that the definition of the unit cell centered around an inversion point is necessary for a well-defined value of the Zak phase (0 oi π) but it is not a requirement for the generation of an edge state For that we calculate the total reflection coefficient of a finite binary photonic crystal using the transfer matrix method The phase of the reflection coefficient can be made dependent on a parameter δ defined in the following way We set the central wavelength of the forbidden band to be λg and determine the quarter wavelength thicknesses to be a0 and b0 for the higher and lower refractive index layers The reflectance and transmittance and respective reflection and transmission coefficients as the phase of the reflection coefficient can be obtained for any combination of a and b such that a = a0(1 + δ) and b = b0(1 − δ) with −1 < δ < 1 The corresponding phase of the reflection coefficient exhibit gradients either positive from 0 to π Outside the forbidden bands the average phase is large and changes abruptly from π to −π of photonic crystals with 7 unit cells on a silica substrate In the upper row the thickness of the layer with higher refractive index is a = a0(1 + δ) nm and the layer with lower refractive index has a thickness b = b0(1 − δ) The initial values of layers are a0 = 70 nm and b0 = 100 nm In the lower row the values are a0 = 135 nm and b0 = 200 nm The choice of the initial thickness of each layer was determined by the central wavelength and the first bandgap λ = 600 nm in the upper row and λ = 1 The parameter δ varies between –1 and 1 The tuning of optical Tamm states is achieved by combining two photonic crystals with layers thickness corresponding to overlapping bandgaps in energy and symmetric gradients (blue and red) of the phase of the reflection coefficient at a predefined wavelength This optical Tamm state results in a narrow transmission line in the middle of bandgap The wavelength of this state at vertical illumination differs from λg = 600 nm due to the small variation of thickness of the layers and the wavelength dependence of the dielectric functions not considered in the optical length equation Schematic representation of a stack based on two photonic crystals of different unit cells The PC2 is designed in order to have a bandgap overlapping with the first bandgap of PC1 Multiple edge states are formed by attaching alternately PC1 and PC2 crystals Reflectance of stacks of two (A) and three (B) photonic crystals producing optical Tamm states in the bandgap The incidence of s-polarized light is from air and the substrate of the stack is silica The optical Tamm states correspond to full transmission lines in the forbidden band indicated by the narrow dark curves in the center of the bandgap the interaction between symmetric edge states produces 4 lines The number of unit cells of the PC2 determines the strength of the coupling and the corresponding frequency splitting width at large number of unit cells the edge state do not interact and both spectral lines degenerate into the single line characteristic of a single edge state The smallest thickness of the PC2 is a single unit cell for which the interaction between edge states and the separation between the corresponding transmission lines is maximum Optical Tamm states in a symmetric structure constituted by 3 one-dimensional photonic crystals The unit cell of the first and the third PCs is made of layers with quarter wavelength thickness The unit cell is built by a central layer of lower refractive index nl and thickness of λ/(4nl) surrounded by two layers of thickness λ/(8nh) of a material with higher refractive index The wavelength λ is selected to be central wavelength of the first bandgap the thickness of the layers of low refractive index can remain the same whereas the thickness of the layer of high refractive index is increased in order to achieve a band inversion In the bandgap the amplitude of the fields decays rapidly except at the wavelengths corresponding to edge states (C) modulus and (D) phase of the electric field across the photonic crystal structure The optical Tamm states are in the middle of the band gap The central OTS have maxima at the boundaries of the photonic crystals and decay in booth directions with the distance Their profiles are almost symmetric and overlap in the both external PCs The profiles of the lateral modes have maxima localized in the central PC2 and decay in both directions Profiles of the modulus of the electric field along the propagation axis for the lateral modes (A) and central modes (optical Tamm states) (B) The formation of multiple edge states based on binary and quaternary units cells was investigated in Bianchi and Kahn (2020). The interplaying between Fabry-Pérot modes and optical Tamm states in structure formed by a photonic crystal and two metallic mirrors was studied in Durach and Rusina (2012) A deeper analysis of the OTS and lateral modes arising in multiple alternating PCs with band inversion and between PCs and plasmomic layers is outside the scope of the present article and will be addressed in other publication In Figure 14 are presented experimental results of the reflectance on two samples measured at quasi-vertical incidence using an objective of small numerical aperture for illumination and light collection (NA = 0.12) The samples were fabricated by alternated deposition of layers of Ta2O5 and SiO2 making a stack of three photonic crystals with 7 The layers of the first and third PC have a nominal thickness of 70 nm (Ta2O5) and 100 nm (SiO2) The nominal thickness of the layers of the central PC are 200 nm (Ta2O5) and 100 nm (SiO2) The spectral shift of the bandgap and resonances are due to fabrication Small changes in the effective layer thickness are due to different distances from each substrate to the crucible and different evaporation angle Despite the limited conditions of the deposition pronounced dips corresponding to the OTS and lateral states are visible in the reflectance spectrum The reflectance dips are probably deeper that measured because the spectrometer used has a spectral resolution of approximately 5 nm Experimental reflectance presenting 4 narrow reflectance dips in the middle and at the edges of the bandgap These dips correspond to optical Tamm states in the symmetric structure constituted by 3 photonic crystals The first and third photonic crystals have 7 unit cells of Ta2O5 and SiO2 of quarter wavelength thickness The central PC has 3 unit cells of the same materials with nominal thickness of 200 and 100 nm Differences between theoretical and effective values of the thickness of each layer depend on the evaporation conditions and are responsible for shifts in the bandgap and position of the resonances λOTS ≈ 584 nm at vertical incidence d12 = 135 nm is exactly half wavelength in ZrO2 of vacuum wavelength λ = 584 nm The higher energy mode (λa = λ1 = 540.3 nm) has an anti-symmetry electric field distribution using as reference the center of the silver layer The mode with lower energy (λs = λ2 = 592.3 nm) has smaller amplitude and is symmetric the symmetric and anti-symmetric modes of a plasmonic thin film are transformed inot a pair of optical Tamm states width symmetric and antisymmetric electric field distribution in the stack Unlike in the symmetric configuration of single plasmonic film requiring evanescent wave excitation the excitation of the both optical Tamm states is here from air Optical Tamm states in a symmetric structure constituted by two identical 7 unit cells photonic crystals and a central thin silver layer (dAg = 30 nm) The layers thickness in the unit cell of both PCs is approximately a quarter of the wavelength θ = 0)|(B) and real (C) and imaginary (D) parts of Ey Profiles of Ey along the z-axis in the stack for vertical incidence of light The vertical lines indicate the boundaries of the photonic crystals and the silver layer In this article three types of resonances with narrow bandwidth involving layered plasmonic media were analyzed: resonances arising in coupled Fabry-Pérot cavities of silver mirrors with heterogeneous intra-cavity media presenting optical cavity strong coupling; hyperbolic layered media based on sub-wavelength layers of plasmonic and dielectric films supporting bulk plasmon modes with large propagation constant and large field amplitudes inside the structure; and finally arising in stacks of photonic crystals and in plasmonic films attached to photonic crystals The resonance anti-crossing in coupled Fabry-Pérot cavities is not only one of the most simple examples of classical strong coupling but also represents a platform with potential in refractive index sensing applications Fabry-Pérot cavities based on distributed Bragg reflectors could also be used for the strong coupling but the total thickness of the stack is much larger and the sensitivity to variations of refractive index of external media much weaker Optical Tamm states present resonant modes with a bandwidth comparable to Fabry-Pérot modes in cavities based on identical distributed Bragg mirrors but their spectral dependence on the angle of incidence differ considerably Multiple OTS modes based on ternary photonic crystal stacks can provide a robust alternative to optical filters based on Fabry-Pérot cavities OTS modes arising in structures including plasmonic layers as the PC-Ag-PC are also useful in sensing applications due to the narrow resonances but can only be restricted to few plasmonic layers owing to the optical absorption the excitation of the two OTS modes with symmetric and antisymmetric field profiles was analyzed for the first time The raw data supporting the conclusions of this article will be made available by the authors The author confirms being the sole contributor of this work and has approved it for publication Some materials used in the preparation of samples were funded by the German Federal Ministry of Education and Research (BMBF) Grant 01DK17040 The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest The author thanks the Institute of Solid State Physics of the Ulm University for the evaporation facilities used in the fabrication of the layered structures and the technicians of the Institute of Experimental Physics for the preparation of substrates 1. ^The upper and lower media can be analyzed even more generally than dielectric and metal as in Yang et al. 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This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) distribution or reproduction in other forums is permitted provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited in accordance with accepted academic practice distribution or reproduction is permitted which does not comply with these terms *Correspondence: Manuel Rodrigues Gonçalves, bWFudWVsLmdvbmNhbHZlc0B1bmktdWxtLmRl Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher 94% of researchers rate our articles as excellent or goodLearn more about the work of our research integrity team to safeguard the quality of each article we publish Ekkehard Peik thought it would take only a few months to create the basic ingredients of a radical new clock when he and his colleague Christian Tamm proposed a device with the potential to be even more precise and portable than the world’s best atomic clocks Prices may be subject to local taxes which are calculated during checkout doi: https://doi.org/10.1038/d41586-024-03891-4 An asymmetric fission island driven by shell effects in light fragments Real-time inference for binary neutron star mergers using machine learning Direct experimental constraints on the spatial extent of a neutrino wavepacket Observation of edge and bulk states in a three-site Kitaev chain The Di Angelantonio-Ieva group is seeking to recruit a highly motivated Postdoc in Genetic Epidemiology/Statistical Genetics in Human Technopole POST-DOCTORAL RESEARCH FELLOW Post Summary of the role The Characterisation & Processing of Advanced Materials HT is an interdisciplinary research institute created and supported by the Italian government whose aim is to develop innovative strategies to pr.. UNIL is a leading international teaching and research institution with over 5,000 employees and 17,000 students split between its Dorigny campus Department of Energy and Environmental Materials As governments worldwide continue their journey toward digitalization, the Middle East is witnessing a remarkable transformation in the realm of e-government services. One of the most innovative partnerships fueling this shift is between Tencent Cloud and TAMM a platform provided by the Abu Dhabi Government that consolidates over 800 services into a single application googletag.cmd.push(function() { googletag.display("desktop-single-halfpage2"); }); The TAMM platform aims to become an indispensable resource for Abu Dhabi’s residents The newly launched platform offers seamless access to a wide array of services What makes TAMM truly stand out is its ability to integrate services from multiple government agencies into a single The TAMM platform serves as a comprehensive gateway to all services provided by the Abu Dhabi Government and monitor your applications seamlessly—all from a single interface googletag.cmd.push(function() { googletag.display("desktop-single-halfpage3"); }); Vice President of Tencent Cloud International for Middle East and Africa describes this collaboration as a significant leap forward for both entities “We are very honored to partner with TAMM to provision the Tencent mini-app platform which empowers them to be a real public service Super App,” says Hu Tencent Cloud is not just working to make e-government services more efficient; it is also pioneering cutting-edge payment solutions in the Middle East A recent innovation introduced by Tencent Cloud is its revolutionary palm print technology which allows users to make payments simply by scanning their palms This technology offers a new level of convenience for users who no longer need to carry smartphones or other devices to make digital payments “We are introducing the palm print technology That means there is a possibility that you don’t need to bring any device and then you can make a payment.” This solution is expected to unlock numerous possibilities for seamless Tencent Cloud faces challenges as a relatively late entrant into the Middle Eastern market Hu acknowledges the obstacles but remains optimistic about the future the challenge and opportunity for us is whether you can provision a very distinguished service and solution to the market,” he explains The company’s unique Super App solutions and wide range of services are expected to carve out a niche for Tencent Cloud in the region Hu also highlights the immense potential of the Middle Eastern market particularly for technology companies looking to expand their global presence “It is a very promising market for technology companies especially for some Chinese technology companies I think most of them are planning to explore opportunities in this region,” he adds Tencent’s innovative solutions are also catching the attention of other regional players expressed his enthusiasm for partnering with Tencent Cloud to bring payment solutions to the region “We have already tested more than 200 million transactions in China and have seen negligible failure rates We are excited to bring this to the region,” says Tikku He is confident that the technology will accelerate the adoption of digital wallets offering consumers unparalleled convenience and rewards Tencent Cloud’s growing influence in the region combined with its strategic partnership with TAMM exemplifies how cutting-edge technology can drive digital transformation in both the public and private sectors and efficient digital solutions continues to grow Tencent Cloud is positioning itself at the forefront of this technological revolution 🪩 The tech behind Taylor Swift’s concert wristbands 🤳 Are you looking for the best dumb phones in 2023 🦄 The 2023 top startups in MENA 🧀 Italian cheesemakers are putting microchips in their Parmesan 🖤 The pros and cons of tattoos 🥦 Your genes can make it easier (or harder) to be a vegetarian ✨ And be sure to follow WIRED Middle East on Instagram, Twitter, Facebook, and LinkedIn Metrics details Graphene Quantum Dots (GQDs) are crucial in biomedicine for sensitive biosensing and high-resolution bioimaging and in photonics for their nonlinear optical properties Integrating GQDs with photonic structures enhances optical properties by optimizing light-matter interactions and enabling precise control over their emission wavelengths we explore a facile synthesis method for GQDs by pulsed laser irradiation in chlorobenzene and highlight the transformative potential of Tamm Plasmon Cavity (TPC) structures for tuning and amplifying the photoluminescence and nonlinear optical properties of GQDs The characterization of GQDs revealed their exceptional properties including efficient optical limiting and stable photoluminescence The study demonstrated that the TPC structure significantly amplifies nonlinear optical effects due to the high light-matter interaction indicating the potential for advanced optical systems including optical limiters and nonlinear optical devices introducing GQDs into the TPC structure leads to a significant enhancement and tuning of fluorescence emission in combination with the confined electromagnetic fields within the TPC increases the spontaneous emission rate of GQDs and subsequently enhances the fluorescence intensity This enhanced and tunable fluorescence has exciting implications for high-sensitivity applications such as biosensing and single-molecule detection TPCs offer a transformative platform for manipulating light-matter interactions and introducing nanoscale confinement that can significantly amplify electromagnetic fields their true potential emerges when paired with nanomaterials the versatile building blocks of the nanotechnology era Enhancing the quantum yield and reducing background noise are essential for overcoming limitations in the sensitivity and selectivity of fluorescence-based sensors and other devices which is a commonly used benzene derivative there are still challenges to be addressed researchers are exploring new methods and techniques for synthesizing GQDs we discuss a facile synthesis method and the properties of GQDs showing their significance for both fundamental research and practical applications We then explored the design principle of TPC structures to revolutionize the fluorescence and optical nonlinearity of GQDs offering exciting prospects for applications in diverse fields ranging from biosensing to telecommunications this is the first paper reporting the synthesis of GQDs by laser irradiation in chlorobenzene which is also a benzene derivative solvent and tuning its fluorescence and nonlinear properties together with a photonic structure (Tamm cavity structure) composed of a minimal number of bilayers of spin-coated silicon dioxide (SiO2) and titanium dioxide (TiO2) as DBR materials Schematic of the GQD formation by PLIL (i) PLIL with a Q-switched Nd:YAG laser (532 nm wavelength 7 ns pulse width and 10 Hz repetition rate) in chlorobenzene along with stirring the liquid (iii) centrifugation done at 6000 rpm for 20 min and (iv) GQDs and b) the fabricated TPC structure with 4.5 bilayers of TiO2 and SiO2 a spacer layer of GQDs incorporated in PVK and a 35 nm thick Ag film and Glacial Acetic Acid (GAA) were used at a volume ratio of 0.3:5:0.42 and vigorously mixed by a magnetic stirrer to make a TiO2 sol and GAA were used at a volume ratio of 0.37:5:0.57 to make a SiO2 sol We used a Jeol/JEM 2100 High-Resolution Transmission Electron Microscope (HRTEM) to confirm the formation of graphene as quantum dots The creation of GQDs was verified by analysing the absorption spectra of the materials at wavelengths ranging from 250 to 900 nm using a UV–visible spectrometer (Shimadzu-UV 2450) The Raman spectrum of the synthesized GQDs was obtained using a LabRAM HR Evolution Raman Spectrometer To study the Fourier transform infrared (FTIR) spectra of the samples a Perkin Elmer Spectrum Two spectrometer was used We optimized the thickness of the TiO2 and SiO2 thin films by measuring the reflectance of the coated films using a Shimadzu-UV 2450 spectrometer Scanning electron microscopy of the fabricated structure was performed with a Gemini 300 Scanning Electron Microscope (SEM) we employed a Q-switched Nd:YAG laser with a 532 nm wavelength We were able to examine the structure's optical limiting (OL) characteristics by plotting the normalized transmittance values against the input fluence We used a Horiba Fluoromax-4 spectrophotometer to examine the fluorescence and lifetime properties of the synthesized GQDs and fabricated structures we used Transfer Matrix simulations in MATLAB and the electric field distribution inside the structure was studied using COMSOL Multiphysics 6.0 b) HRTEM images of GQDs in chlorobenzene (inset of (b) shows the magnified image of a single quantum dot with an interplanar spacing of 0.21 nm indicating the (100) plane of the crystalline structure (c) particle size distribution histogram showing an average size of 6.5 nm (d) Raman spectrum of GQDs with the D and G bands (e) the comparison of FTIR spectra of colloidal GQDs and pure chlorobenzene indicating the lack of functional changes after laser irradiation and (f) absorption spectrum of GQDs in chlorobenzene with a characteristic peak at approximately 286 nm (inset shows the appearance of colloidal GQDs under visible light) indicating the presence of structural disorder which suggests a moderate level of ordered graphitic structure and defect density and the absence of significant absorption in the visible range (400–700 nm) makes them an efficient candidate for incorporation as a defect material in a photonic crystal for NLO studies (a) Z-scan profiles of the sample at different energies and (b) corresponding optical limiting characteristic plots showing an optical limiting threshold of 3.87 J/cm2 for the GQDs The theoretical model that best matches the experimentally observed data the effective nonlinear absorption (NLA) coefficient may be found using the nonlinear pulse propagation equation given by (a) Photoluminescence spectra of GQDs in chlorobenzene at different excitation wavelengths ranging from 320 to 430 nm (the inset shows the fluorescence of GQDs under UV light) (b) the fluorescence decay profile of the synthesized GQDs and the prompt and (c) CIE chromaticity diagram for GQDs showing the scope for blue-emitting LEDs The diagram is a two-dimensional plot with axes labelled x and y and it represents all the chromaticities that the human eye can perceive The colour purity of an LED is determined by the position of the x and y coordinates of the LED along this line The findings suggest that GQDs hold significant promise as materials suitable for optical devices These materials could serve as viable options for blue LEDs powered by UV chips finding applications across various advanced technologies (a) Reflectance spectra of the DBR for different numbers of bilayers starting from the TiO2 layer (b) photograph of the fabricated TPC structure (inset is a photograph of the DBR) (c) comparison between the obtained reflectance spectra of the DBR and TPC (d) comparison between the simulated reflectance spectra of the DBR and TPC (e) angular dispersion of the transmittance of the fabricated TPC structure showing the transmittance mode (f) simulated angular dispersion of the transmittance of the TPC structure (g) cross-sectional SEM image of the TPC structure where each layer aligns with the layers of the structure and h) simulated electric field distribution in the TPC structure at 532 nm showing a sevenfold enhancement in the electric field within the TP cavity which can provide valuable insights into the behaviour of the TPC structure such as the position and intensity of the electric field This indicates a sevenfold field enhancement at the spacer layer which in turn enhances the light-matter interaction (a) Comparison of the OA Z-scan plots of the TPC and the GQD/PVK reference film (the inset shows the SA characteristics of a 35 nm Ag film) at 0.07 GW/cm2 on-axis intensity and (b) corresponding OL plots showing the limiting threshold value of the TPC structure as 0.19 J/cm2 demonstrate the ability of our structure to perform as an efficient optical limiter This implies that our structure can improve the performance and efficiency of different optical systems and devices the ability to control and manipulate these nonlinear interactions holds significant promise for the development of advanced photonic devices including those such as all-optical switches and optical modulators Photoluminescence investigations of the TPC structure revealed a substantial departure from the PL spectrum of the GQD/PVK reference film (Fig. S1a in the supporting information) We obtained the maximum emission of the GQD/PVK reference film when excited at 346 nm rather than at 380 nm we performed PL investigations on every film sample using an excitation wavelength of 346 nm the spectral profile of the reference film is different from that of colloidal GQDs which are characterized by wide PL emission the reference film has a narrower emission profile that is blue shifted and its maximum emission occurs at 433 nm when excited at a wavelength of 346 nm This discrepancy can be attributed to various factors including the physical shape of the material and other elements that collectively modify the photoluminescence spectrum These variations can impact both the wavelength and intensity of light emitted by the material thus influencing the observed photoluminescence spectrum The excitation spectrum of the GQD/PVK reference film for emission peaks at approximately 433 nm is given in the supporting information (Fig. S1b) the emission spectra of the TPC exhibit intriguing behavior as shown in Figure S1c in the supporting information A tunable emission spectrum is observed with changes in the angle of incidence of the excitation wave When we increase the angle of incidence from 0° to 70° the emission peak shifts towards shorter wavelengths accompanied by a notable increase in the emission intensity This wavelength shift aligns with the changes observed in the transmittance spectra of the TPC as a function of the angle of incidence (a) A comparison between the obtained reflectance spectra of DBR-2 and TPC-2 showing the TPC mode inside the bandgap of DBR-2 (b) angular dispersion of the transmittance of the TPC-2 structure showing the angle tunable transmittance mode (c) PL spectra of the TPC-2 structure for different angles of incidence at 346 nm excitation wavelength (d) a comparison of the obtained emission profile of TPC-2 with its transmittance spectra for different angles of incidence showing the tuning of fluorescence aligned with the transmittance mode shift from 484 to 417 nm and (e) a comparison of the fluorescence decay profile of reference-2 and TPC-2 showing the lifetime quenching of TPC-2 (the decay profile of the prompt is also shown) TPC-2 exhibits unique PL spectra with a very distinct peak that can be tuned from 484 to 417 nm by solely changing the angle of incidence from 0 to 70 degrees the confined wavelength corresponds to the resonance wavelength at which light is effectively trapped or confined within the structure Changing the angle of incidence (excitation angle) changes the optical path length and thus the resonance condition The maximum photoluminescence intensity is observed when the emission wavelength and resonance mode coincide The local density of optical states is altered within the Tamm plasmon cavity This indicates that the fluorophores have more accessible photon states for emission the spontaneous emission rate of the fluorophores increases they release photons faster than they would in free space leads to an increase in the radiative decay rate of the fluorophores more of the excited fluorophores undergo radiative decay and emit photons which results in higher fluorescence intensity at the resonance wavelength The radiative decay rates in the cavity and free space can be expressed as \({\Gamma }_{0}=\frac{1}{{\uptau }_{0}}\) and \({\Gamma }_{c}=\frac{1}{{\uptau }_{c}}\) where \({\uptau }_{0}\) is the radiative lifetime of the emitter in free space and \({\uptau }_{c}\) is the radiative lifetime of the emitter when coupled to the cavity fluorescence tunability allows precise control of emission properties facilitating multiplexed sensing and reducing spectral overlap in complex samples The ability to tailor the fluorescence characteristics of probes enhances selectivity and enables the design of sensors optimized for specific applications These advancements collectively contribute to improved accuracy and expanded applicability of fluorescence-based sensing technologies making them invaluable tools in scientific research This adaptability allows researchers and engineers to optimize the properties of GQDs for maximum performance within the TPC structures This combination allows for precise tuning of optical properties resulting in improved light-matter interactions and a stronger Purcell effect which leads to enhanced fluorescence and nonlinear optical responses the compact and efficient nature of TPCs makes them suitable for integration into miniaturized devices and applications Although the integration of GQDs with TP structures offers exciting potential for different applications there are some limitations and thresholds in terms of the enhancement effect and scalability for practical applications There are challenges in scaling up the production of TPCs while maintaining precise geometries and uniformity across larger areas Material selection must account for compatibility with GQDs and other system components considering properties such as the refractive index While increasing the number of bilayers can improve the quality factor and light confinement it also increases the complexity of the fabrication process and may affect the overall device size The Purcell effect is dependent on the quality factor and mode volume of the TPCs which may vary and impact the degree of enhancement Thermal effects from high laser intensities can affect stability and performance careful optimization and ongoing research can facilitate practical solutions such as refining material compatibility and enhancing mode matching for maximum enhancement Efficient thermal management and reduced photon loss will ensure consistent performance and long-term stability paving the way for scalable and reliable TPC/GQD-based technologies GQDs were synthesized by a facile laser irradiation method and the ability of TPC structures to improve their optical properties was explored GQDs have shown promising characteristics for diverse applications They exhibited notable nonlinear optical behavior attributed to TPA making them potential candidates for optical-limiting applications they displayed efficient fluorescence and favourable chromaticity indicating their suitability for use in advanced technologies particularly in the development of blue LEDs The incorporation of GQDs into a TPC structure resulted in a 43-fold increase in the nonlinear absorption coefficient due to enhanced light-matter interactions Optical limiting studies of the structure showed a limiting threshold value of 0.19 J/cm2 demonstrating the structure's efficiency in acting as an optical limiter Photoluminescence studies showed tunable and enhanced emission spectra in the TPC structures attributed to the Purcell effect The angular dispersion characteristics of the transmittance of the TPC structure indicated that the structure operates as an angle-tunable frequency filter The findings highlight the potential of tailoring TPC structures integrated with GQDs for improved performance in various fields especially in advanced sensing applications emphasizing their enhanced optical limiting properties and tunable fluorescence characteristics Data are available from the corresponding author on reasonable request Interplay of resonant cavity modes with localized surface plasmons: Optical absorption properties of bragg stacks integrating gold nanoparticles Surface plasmon-assisted fluorescence enhancing and quenching: From theory to application Plasmonics: Merging photonics and electronics at nanoscale dimensions Tamm plasmon polariton in planar structures: A brief overview and applications Tamm plasmon polaritons: Slow and spatially compact light Purcell effect in Tamm Plasmon structures with QD emitter Tamm Plasmons directionally enhance rare-earth nanophosphor emission Coupling of fluorophores in single nanoapertures with Tamm Plasmon structures Impressive nonlinear optical responses of a cationic porphyrin derivative in a flexible all-polymer Bragg stack on optical Tamm mode coupling Generation of Tamm Plasmon resonances for light confinement applications in narrowband gradient-index filters based on nanoporous anodic alumina Tunable optical bistability in graphene Tamm plasmon/Bragg reflector hybrid structure at terahertz frequencies Narrowband thermal emission realized through the coupling of cavity and Tamm Plasmon resonances Nanoparticle shape optimization for tamm-plasmon-polariton-based organic solar cells in the visible spectral range and tunable photodetection in the near-infrared with Au/TiO2 nanodiodes based on Tamm plasmons Graphene quantum dots: A comprehensive overview and prospects of graphene quantum dots: A comprehensive review Fluorescence and sensing applications of graphene oxide and graphene quantum dots: A review Recent advances in graphene quantum dots for sensing Recent advancement in graphene quantum dots based fluorescent sensor: Design and challenges of graphene quantum dots (GQDs) Density functional theory investigation of nonlinear optical properties of T-graphene quantum dots Liquid-phase laser ablation synthesis of graphene quantum dots from carbon nano-onions: Comparison with chemical oxidation Linear and nonlinear optical properties of graphene quantum dots: A computational study Fluorescence and nonlinear optical response of graphene quantum dots produced by pulsed laser irradiation in toluene Measurement of the third order optical nonlinearities of graphene quantum dots in water at 355 nm Generation of graphene quantum dots by the oxidative cleavage of graphene oxide using the oxone oxidant Rational hydrothermal synthesis of graphene quantum dots with optimized luminescent properties for sensing applications Solvothermal method to prepare graphene quantum dots by hydrogen peroxide Synthesis of graphene oxide and graphene quantum dots from miscanthus via ultrasound-assisted mechano-chemical cracking method Progress in microwave-assisted synthesis of quantum dots (graphene/carbon/semiconducting) for bioapplications: A review Synthesis of graphene quantum dots and their applications in drug delivery Synthesis and applications of graphene quantum dots: A review Efficient bottom-up synthesis of graphene quantum dots at an atomically precise level Advances in synthesis of the graphene quantum dots from varied raw materials Luminescent graphene quantum dots fabricated by pulsed laser synthesis Impact of photonic band edge enabled slow light effect on optical limiting activity of graphene quantum dots in all polymer 1-D photonic crystals Laser irradiation construction of nanomaterials toward electrochemical energy storage and conversion: Ongoing progresses and challenges Fundamentals and comprehensive insights on pulsed laser synthesis of advanced materials for diverse photo- and electrocatalytic applications Evolution and synthesis of carbon dots: from carbon dots to carbonized polymer dots High-speed photography of laser-induced breakdown in liquids Nonaqueous sol-gel routes to metal oxide nanoparticles Metal oxides nanoparticles via sol–gel method: a review on synthesis Synthesis and characterization of TiO2/SiO2 thin film via sol-gel method in IOP Conference Series: Materials Science and Engineering vol A comprehensive study of spin coating as a thin film deposition technique and spin coating equipment A theoretical study on spin coating technique Transfer matrix based reverse engineering approach to analyse annealing induced changes in optical transmission of TiO2/Ag/TiO2/Ag multilayer From small aromatic molecules to functional nanostructured carbon by pulsed laser-induced photochemical stitching in Encyclopedia of Analytical Chemistry (John Wiley & Sons Third-order nonlinear optical studies of newly synthesized polyoxadiazoles containing 3,4-dialkoxythiophenes Hydrothermally grown VS 2 nanosheets: A material for optical limiting applications A REVIEW OF OPTICAL LIMITING MECHANISMS AND DEVICES USING ORGANICS Photoluminescence from chemically exfoliated MoS2 Photoluminescent colloidal Cu@C-NPs suspensions synthesized by LASL in (Digital Printing Technologies; IS&T’s NIP16 Enhanced third-order nonlinear optical response of gold@carbon (Au@C) core-shell due to Tamm-plasmon cavity Coupling of the Tamm Plasmon to the BODIPY fluorophore in photonic crystals for nonlinear optical applications Optical field enhanced nonlinear absorption and optical limiting properties of 1-D dielectric photonic crystal with ZnO defect Nonlinear optical studies of [Pt17(CO)12(PPh3)8]n+ metal nanoclusters and their enhancement via all-plastic photonic crystal cavity Photonic cavity-mediated tunable ultrafast absorption dynamics in BaTiO3-based one-dimensional photonic crystal Controlled atomic spontaneous emission from Er3+ in a transparent Si/SiO2 microcavity Environmentally responsive nanoparticle-based luminescent optical resonators Spontaneous emission probabilities at radio frequencies in Confined Electrons and Photons: New Physics and Applications (ed Ultrafast photonic crystal nanocavity laser Photonic crystal circular nanobeam cavity laser with type-II GaSb/GaAs quantum rings as gain material Sensing and detection capabilities of one-dimensional defective photonic crystal suitable for malaria infection diagnosis from preliminary to advanced stage: Theoretical study in Reviews of Environmental Contamination and Toxicology: Continuation of Residue Reviews (ed Download references We thank Calicut University and SAIF MGU for the PL measurements and STIC India for the TEM analysis Sanjay Subramaniam & Chandrasekharan Keloth The synthesis and characterization of the material and structures were performed by the author H.J.E provided valuable suggestions to improve the experiment and correct the manuscript supervised the experiment and corrected the manuscript Download citation DOI: https://doi.org/10.1038/s41598-024-62694-9 Department of Government Enablement - Abu Dhabi launches TAMM 3.0 The Department of Government Enablement (DGE) has launched TAMM 3.0 at GITEX Global 2024. This AI-powered platform marks a major advancement in the delivery of government services in Abu Dhabi. In collaboration with other Abu Dhabi government entities DGE is setting a new benchmark in digital government through TAMM’s one-stop-shop featuring a unified app and portal offering over 800 seamless services through a personalised highly intuitive platform designed to meet the evolving needs of citizens The TAMM 3.0 launch is part of the Abu Dhabi Government’s Digital Strategy and the UAE’s National AI Strategy 2031 guided by a vision to enhance the lives of citizens and investors by improving public services through advanced technologies and innovation His Excellency Ahmed Tamim Hisham Al Kuttab Chairman of the Department of Government Enablement – Abu Dhabi, said: “The launch of TAMM 3.0 is a pivotal step in further enhancing Abu Dhabi government service delivery in line with the visionary objectives of Abu Dhabi’s leadership to realise seamless AI-powered solutions that elevate public services In close collaboration with numerous other Abu Dhabi government entities we are enabling a new standard in digital government and proactive services ensure that Abu Dhabi government entities work together towards one meaningful goal which is to consistently meet the evolving needs of citizens and residents.” TAMM 3.0 is designed to provide a highly personalised experience for each user features conversational voice capabilities allowing users to interact through voice commands in Arabic and English while advanced algorithms analyse user behaviour and preferences to tailor services and recommendations paying utility bills or configuring an automated payment TAMM 3.0 offers a multitude of AI-enabled government services integrated into a single platform This comprehensive integration underscores DGE’s commitment to providing efficient accessible and future-ready government services to Abu Dhabi’s constituents TAMM Care has also been further enhanced within TAMM 3.0 to ensure an advanced customer experience with the Unified Abu Dhabi Government Contact Centre and the TAMM Unified Service Centres including responsive and proactive support powered by real-time dashboards and with a Customer-360 view derived from Abu Dhabi Government’s Unified CRM TAMM has expanded its Live Support services to include video and audio channels This allows customers to engage directly with a TAMM agent virtually hands-on assistance from the comfort and privacy of their homes The expanded service enhances accessibility and boosts customer satisfaction through focused enables TAMM agents to pinpoint and resolve customer issues efficiently while maintaining user privacy TAMM teams actively monitor interactions and intervene to pre-empt or address any potential challenges In parallel, TAMM Nexus was introduced to revolutionise the Product Delivery Life Cycle within TAMM, leveraging AI across all phases (ideation This translates to a potential 70-80 per cent increase in speed This AI-powered approach enables a more agile and rapid iteration process significantly accelerating the delivery of new services on the TAMM platform TAMM Nexus ensures that new features can be rolled out faster with higher standards of quality and security aligning with the broader goals of digital innovation and service excellence said: “Our mission is to continuously challenge the status quo and elevate the experience and improve the quality of life for citizens Contributing to DGE’s ambition towards an AI-native government TAMM 3.0 delivers against this mission and provides a truly personalised experience that puts the needs of every customer at the centre of Abu Dhabi Government’s unified TAMM omnichannel and services one-stop shop we are equipping our customers with their own AI assistant that knows them and their unique needs and that is making government interactions more personalised ensuring that every touch point is user-friendly and tailored to each individual’s unique preferences.” TAMM’s AI Assistant allows real-time and contextualised responses to customer’s queries and applications TAMM 3.0 has the required context and capability to provide instant feedback making government services faster and more efficient Not only does this real-time capability enhance the user experience it also significantly reduces the administrative burden on government entities the platform is set to evolve even further incorporating new features and services that will continue to push the boundaries of what digital government can achieve The launch of TAMM 3.0 at GITEX 2024 marks a significant milestone in Abu Dhabi’s journey toward becoming a global hub for innovation and technology-driven government and cements the emirate’s position as a global leader and pioneer in this space Department of Government Enablement – Abu Dhabi launches CX Spaces on TAMM The Department of Government Enablement (DGE) has made a pivotal move to elevate customer experience across Abu Dhabi’s Government services through its CX Spaces on the TAMM app a key initiative within DGE’s CX focus for the next two years Designed to simplify and enhance accessibility to government services CX Spaces reflects a people-centric approach aligning government operations more closely with the needs of the public.  which includes dedicated spaces for business and properties will consolidate essential services into integrated By streamlining services such as property transactions and business licensing CX Spaces is set to revolutionise how services are provided in Abu Dhabi personalised Spaces that cater to customer needs across all sectors Built on the core principles of Closer to the People the CX approach is designed to foster stronger connections with the public through co-designed Leveraging advanced AI-driven technologies and data insights these initiatives will introduce personalised services simplifying everything from healthcare appointments to property transactions Feedback from more than 600,000 data points collected in collaboration with more than 100 leaders from 30 government entities has been integral to shaping this initiative The program addresses the needs of citizens and the CX Think Tank—initiatives that position Abu Dhabi as a global leader in customer experience excellence emphasised the long-term vision behind these efforts the Abu Dhabi Government has continuously evolved how government services are delivered By putting citizens and residents at the core of our service design we are enhancing the customer experience and ensuring that Abu Dhabi maintains its leadership in digital governance innovation “In collaboration with other Abu Dhabi Government entities DGE is dedicated to developing services that meet the changing needs of our people future-ready government experience for all.” Executive Director of the Customer Experience Sector at DGE and said: “Our goal is to design the future of customer experience by making public services more intuitive and easier to use ensuring that they become truly effortless for the people who rely on them Abu Dhabi government entities will operate within a unified ecosystem to guarantee smooth and effective execution of our CX programs tangible improvements for the entire community.” The current CX roadmap builds upon the achievements of the Abu Dhabi Program for Effortless Customer Experience and seeks to bring even greater enhancements to the customer journey By embracing advanced technologies and fostering collaboration across government entities these new CX initiatives will create a cohesive future-proof government experience that addresses the ever-evolving needs of citizens Department of Government Enablement - Abu Dhabi and Abu Dhabi Government entities add new AI-powered services to TAMM 3.0 platform during GITEX Global 2024 The Department of Government Enablement – Abu Dhabi (DGE) has unveiled a series of AI-powered features and capabilities on its upgraded TAMM 3.0 government services platform at GITEX Global 2024 offering a suite of new and improved services designed to provide citizens and businesses in Abu Dhabi with a more seamless Key upgrades include the introduction of an AI assistant capable of real-time interactions via a chat function and AI-enabled bill payments through the enhanced Abu Dhabi Pay such as vehicle license and Emirates ID renewals have been significantly streamlined to reduce effort and elevate the overall customer experience These transformative enhancements underscore Abu Dhabi's vision of establishing an AI-native government reinforcing its position as a digital leader His Excellency Ahmed Tamim Hisham Al Kuttab, Chairman of the Department of Government Enablement – Abu Dhabi (DGE), said: “We are proud to showcase TAMM 3.0 at GITEX Global 2024, a pivotal component of Abu Dhabi’s Digital Strategy. This initiative exemplifies our commitment to transforming public service delivery through collaboration with other Abu Dhabi Government entities By unifying our services on an AI-powered platform we empower residents to navigate their needs with unparalleled ease enhancing their overall experience.” said: “TAMM 3.0 is not just about streamlining services; it represents a transformative approach for the government By harnessing advanced AI technologies and collaborating with various Abu Dhabi Government entities we are setting a new benchmark for service excellence and efficiency Our goal is to create a future-ready government that continuously adapts to the needs of our citizens These AI-driven enhancements underscore Abu Dhabi's commitment to digital transformation introducing innovative solutions that elevate user experience and simplify access to government services and the Department of Energy (DOE) TAMM 3.0 aims to transform service delivery by integrating more than 800 services into a unified platfrom designed to meet the evolving needs of the community offers 24/7 support through voice capabilities in both Arabic and English By analysing user behaviour and preferences the assistant tailors services to ensure every interaction is relevant and efficient Abu Dhabi Pension Fund launches Register Your Interests and Expertise initiative for pensioners via TAMM Government Affairs Abu Dhabi Pension Fund (ADPF) has invited pensioners to participate in the recently launched Register Your Interests and Expertise initiative, now available on the TAMM platform. The initiative aligns with Abu Dhabi Government’s commitment to improving citizens’ quality of life by supporting pensioners and enhancing the services provided to them The fund explained that the initiative seeks to better understand pensioners by allowing them to share insights into their professional backgrounds pensioners can select from various thoughtfully designed pathways to share their hobbies allowing the fund to develop innovative social programmes based on accurate data-driven insights into pensioners’ real needs The initiative also allows pensioners to register information about their professional expertise which will be added to ADPF’s database of experts This database will help them contribute their knowledge and experience to serve the nation in the future His Excellency Khalaf Abdullah Rahma Al Hammadi emphasised that this step is part of the fund’s strategic plan to enhance the role of pensioners and support them in various aspects of life His Excellency explained that based on pensioner inputs and analysis ADPF will collaborate with strategic partners to develop and implement sustainable programmes and initiatives These efforts aim to support pensioners and their families by enriching their quality of life and providing the necessary care and support Pensioners can register their interests and expertise via ADPF’s digital services on the TAMM platform or through the Register Your Interest page on the official ADPF website at pension.gov.ae Most Valuable Promotions (MVP) announced today that two-time Canadian Olympian and amateur world champion Tammara “Tamm” Thibeault will be the newest signee to MVP’s growing roster of world-class fighters Thibeault joins MVP just ahead of her highly-anticipated pro debut against fellow Canadian and the #10 WBA-ranked middleweight a passionate advocate for gender equality in the sport is making a powerful statement from the opening bell of her professional career as the first female boxer in history to compete in a pro debut under men’s rules—four three-minute rounds—in a middleweight / 160 lbs bout against Spence The bout will open the main card of MVP’s Most Valuable Prospects 10 on Friday available globally as part of the DAZN subscription package with Boxlab Promotions serving as the official licensed promoter and fellow Canadian signee Lucas Bahdi will be in attendance to support Thibeault and fellow MVP star Wanna Walton Thibeault began her boxing journey at the age of nine a former CFL athlete who took up boxing in his offseason knock out an opponent during a Provincial tournament she took up boxing at age 12 and was inspired to compete for Canada while watching the first women’s Olympic boxing competition at the 2012 London Olympics has forged an outstanding career in the amateur ranks Thibeault made her Olympic debut at Tokyo 2020 where she advanced to the quarterfinals of the women’s 75kg (165lb) event matching Canada’s best-ever Olympic result in any women’s boxing event She went undefeated until she returned to the Paris Olympics in 2024 earning gold medals at the 2022 IBA Amateur World Championship recently completed a Bachelor’s degree in Urban Studies from Concordia University in 2023 which she earned over seven years while competing where she is earning a one-year Master’s degree in urban design and urban planning while training at the renowned Steel City Gym She is now poised to embark on the next chapter of her career setting a new precedent in the pro ranks as the first female boxer in history to make a pro debut while competing under men’s rules on the main card of MVP’s Most Valuable Prospects 10 “I am beyond excited to be part of Most Valuable Promotions,” said Tamm Thibeault “The moment has come to start a new adventure I will have the opportunity to bring something great to women’s professional boxing Amanda Serrano has been an incredible inspiration and I’m proud to follow her example by competing under men’s rules—with three-minute rounds—against Natasha Spence in my pro debut today and I can’t wait to start this amazing journey!”  “I’m thrilled to welcome another strong female fighter in Tamm Thibeault to the MVP family,” said Amanda Serrano “Tamm’s impressive accomplishments at the amateur level speak volumes about her talent and potential and I’m confident she’s destined to become a future superstar she shares our vision to uplift female fighters and show the world that women deserve recognition By stepping into the ring to compete with three-minute rounds in her first pro fight Tamm is making a bold statement on equality and setting a powerful example for the next generation of women in boxing “Tamm Thibeault has the skills inside and outside the ring to ensure she has a long and successful boxing career,” said Jake Paul and Nakisa Bidarian “As a two-time Canadian Olympian and amateur world champion Tamm has already proven herself as one of the sport’s brightest rising stars Her decision to compete under men’s rules in her professional debut is a groundbreaking moment and we’re honored to support her as she sets a new standard for what’s possible in women’s boxing The anticipation for her pro debut on Most Valuable Prospects 10 tonight is just the beginning and we’re excited to see her continue inspiring athletes worldwide and showcasing her talents in an MVP event in Canada in 2025 Thibeault joins MVP’s elite roster of superstar athletes and up-and-coming stars including international superstar Jake “El Gallo” Paul boxing trailblazer and unified featherweight world champion Amanda “The Real Deal” Serrano multi-talented megastar Javon “Wanna” Walton India’s most successful professional boxer Neeraj Goyat and top-ranked lightweight “Prince” Lucas Bahdi Subscribe«Prev1 /797Next»Body Shot… and It Folded Him Instantly 🥶🥊 #Boxing #LiverShotKhamzat Chimaev Putting in Work 👊 #KhamzatChimaev #MMAFans Roasting Michael Bisping Never Gets Old 😂 #UFC #BispingAlex Pereira and Yousri Belgaroui Sharpen Each Other in Sparring 💥🥊 #MMA #Kickboxing«Prev1 /797Next» Tamm Kritzer has affected meaningful change that allows us to better serve our patients and communities Essentia is proud to announce that Kritzer’s next role with the organization will be senior vice president of hospital operations at St Mary’s through the COVID-19 pandemic while a new hospital was being built via the Vision Northland project “I am deeply committed to the Essentia mission and am excited to engage and partner with others to deliver on that mission,” Kritzer said Mary’s hospital provides an opportunity to innovate and transform how we deliver high-quality health care in a sustainable manner.” Kritzer has more than 30 years of experience in health care supporting our practices in northwest Wisconsin she was instrumental in improving care — and enhancing access to that care — in many of the small towns Essentia is privileged to serve “I am passionate about rural health care,” she said “I grew up in rural Minnesota and I am excited to be a catalyst to bring innovation and creative problem-solving to our teams.” Kritzer will oversee a hospital with 344 rooms — 342 of which are private — and the region’s only Level I Adult Trauma Center It opened last July following completion of a four-year $900 million project that added 942,000 square feet of new and renovated space to our downtown campus Kritzer earned a master’s degree in business administration from the University of St Paul and a bachelor of arts degree in health information management from the College of St Like most websites, we use cookies and other technologies to keep our website reliable, secure, and to better understand how our site is used. By using our site, you agree to our use of these tools. Learn More Metrics details Surface enhanced Resonance Raman spectroscopy (SERRS) is a powerful technique for enhancing Raman spectra by matching the laser excitation wavelength with the plasmonic resonance and the absorption peak of biomolecules we propose a tunable Tamm plasmon polariton (TPP) cavity based on a metal on distributed Bragg reflector (DBR) as a scalable sensing platform for SERRS We develop a gold film-coated ultralow-loss phase change material (Sb2S3) based DBR which exhibits continuously tunable TPP resonances in the optical wavelengths We demonstrate SERRS by matching the TPP resonance with the absorption peak of the chromophore molecule at 785 nm wavelength We use this platform to detect cardiac Troponin I protein (cTnI) a biomarker for early diagnosis of cardiovascular disease This scalable substrate shows great promise as a next-generation tunable biosensing platform for detecting disease biomarkers in body fluids for routine real-time clinical diagnosis all reported plasmonic structures are passive meaning that their plasmonic resonance is fixed for a specific excitation frequency only a limited number of biomolecules whose absorption peak wavelength corresponds with the plasmonic resonance wavelength can be detected using SERRS an active plasmonic substrate is necessary for SERRS to continuously tune its plasmonic resonance wavelength This allows for the exact matching of the absorption peak wavelength of target biomolecules achieving the highest possible enhancement a single SERRS substrate with multiple plasmonic modes can detect various biomolecules due to the tunability of the plasmonic resonance wavelength This system also shows small TPP resonance tunability in the MIR frequencies due to the underlying mechanism of changing the carrier concentration of CdO it is necessary to tune the photonic bandgap (PBG) of DBR since the TPP resonance is excited within the PBG It is also noted that TPP cavities are not yet proposed for SER(R)S applications we demonstrate large TPP resonance tunability in the near-infrared (NIR) spectral band by tuning the PBG of DBR we develop an ultralow-loss chalcogenide phase change material (PCM) based tunable DBR where the PBG spectral band can be tuned by switching the structural phase of PCM from amorphous to crystalline We show the excitation of narrow linewidth TPP modes by depositing a thin metal layer on top and bottom of the tunable DBR and demonstrate continuous tuning of TPP resonance by direct annealing and electrical heating As one of the potential applications of the tunable TPP cavity we demonstrate the SERRS with enhanced sensitivity by matching the second-order TPP resonance of the scalable Tamm cavity with the absorption peak of Raman reporter molecule at 785 nm excitation wavelength We also performed a proof-of-concept biosensing application using the TPP cavity by detecting one of the cardiovascular disease (CVD) biomarkers such as cardiac Troponin I (cTnI) protein at biologically relevant concentrations a SEM image of fabricated five bilayers of Sb2S3-SiO2 DBR The reflection spectrum of DBR at normal incidence for both amorphous (Amp) and crystalline (Cry) phases of Sb2S3 (b) Calculated and (c) Measured Two-dimensional (2D) maps of angular reflection spectra of DBR are shown in (d) to (g) For p-polarizations (d) Calculated and (e) Measured For s-polarization (f) Calculated and (g) Measured we show the measured reflection spectrum of DBR at normal incidence for both amorphous and crystalline phases of Sb2S3 The experimental results show a good agreement with the calculated results the fabricated DBR provides tunable dual photonic bandgaps in optical wavelengths b Calculated and measured reflection spectra at normal incidence 2D maps of angular reflection spectra of the TPP cavity are shown in (c) to (f) For p-polarization (c) calculated and (d) measured For s-polarization (e) calculated and (f) measured a Measured reflection spectra of TPP cavity when Sb2S3 is in Amp phase and annealed at 230 °C Continuous tuning of TPP resonance wavelength with an increase in temperature for (b) second-order TPP and (c) first-order TPP d Electrical continuous forward tuning of second order TPP mode using a microheater integrated TPP cavity the resonance wavelength can be precisely tuned by properly selecting an external stimulus such as temperature or electric current a Measured SERS spectrum of reference cavity using 0.1 mM and 1 μM cyanine dye concentrations b Measured SERRS spectrum of TPP cavity using 1 μM Zoomed SERRS spectrum of 100 nM and 10 nM concentrations are shown in the inset of b All SER(R)S spectra were subtracted from the background (dark) spectra c Intensity mapping of 943 cm−1 peak from cy7.5 dye d SERRS spectra of the representative Raman band at 698 cm−1 show an increase in SERRS intensity with an increase in the concentration of cTnI protein e The maximum number of cTnI molecules (Nmax) adsorbed in the illuminated sensor area versus the corresponding Raman intensity shift (ΔI) with respect to a blank sample for different cTnI concentrations The red curve represents the theoretical fit ΔI is calculated using 720 cm−1 Raman band we show the SERRS spectra from the cy7 corresponding to various biologically relevant cTnI cardiac biomarker protein concentrations ranging from 1.9 nM to 380 fM We performed a proof-of-concept study in which we spiked thiolated cTnI proteins into a solution of 0.5 mg/mL BSA (Bovine Serum Albumin) (see Methods) We prepared these different spiked concentrations (1.9 nM to 380 fM) of cTnI into the sample vial containing BSA The sensitivity of the sensor can be further improved by engineering the morphology of the sensing surface The spectral tunability of TPP mode can also be used to mitigate the fabrication error The ease of fabrication using thin film deposition techniques the optical excitation without using any coupling techniques polarization and incident angle independent response and high resonance quality factor modes with tunable features make the TPP cavity a potential scalable sensing platform for practical SERS applications The proposed tunable TPP cavity can be used for other potential applications such as refractive index sensors The DBR samples were fabricated by the sequential deposition of Sb2S3 and SiO2 thin films on quartz and silicon substrates the substrates were pre-cleaned using acetone and SiO2 were deposited using RF magnetron sputtering To achieve uniform deposition of thin films the distance between the substrate and target was kept at 15 cm Room temperature deposition under a high-purity argon (99.999%) atmosphere at a deposition pressure of 10 mTorr was carried out To switch the structural phase of Sb2S3 layers in the DBR from amorphous to crystalline the samples were annealed at 250 °C on a hot plate for 15 min the thin layer of Au was deposited using the thermal evaporation technique at a deposition rate of 0.1 A/s samples were annealed at 230 °C on a hot plate for 5 min to avoid the increased surface roughness of the film Microheater fabrication and Temperature calibration: Using UV illumination-based photolithography the metallic microheater was fabricated on a Si substrate Tungsten (W) was used as the heater metal and 200 nm thick W film was deposited over the entire area using DC magnetron sputtering and followed by a lift-off process to leave behind the W only in the patterned area The microheater was then subjected to temperature calibration using a source meter (Keithley 2450) Two probes were used to apply the DC current to the heating element and a thermocouple was mounted at the center of the microheater to monitor the temperature change with applied current To fabricate microheater-integrated TPP cavities and Au were directly deposited in the whole area of the sample 2D nanohole grating fabrication: A focused (gallium)-ion beam (FEI Helios NanoLab 600) was used to fabricate 2D nanohole gratings By using FIB with a beam current ≤18 pA and dosage of 10 mC/cm2 we milled on 30 nm thick Au thin film deposited on the Sb2S3 termination layer of DBR The patterned grating area was 30 µm x 30 µm A scanning electron microscope (FEI Helios NanoLab 600) was used for imaging the cross-section and surface morphology of the samples The surface roughness of the samples was determined using an atomic force microscope (Burker) Variable-angle high-resolution spectroscopic ellipsometry (J.A V-VASE) was used to determine the thickness and the optical constants of Sb2S3 The normal incidence reflectance measurements were performed using a microspectrophotometer (Jasco MSV-5200) with a sampling domain size of 100 μm × 100 μm and 25 μm × 25 μm for scalable and nanopatterned TPP cavities The reflection measurement of microheater-integrated samples was performed using a sampling domain size of 25 μm × 25 μm Angular reflection measurements of scalable TPP samples were performed using a variable angle spectroscopic ellipsometry with a beam spot size of 2 mm × 2 mm (J.A The normal incidence transmission measurements of scalable TPP samples were performed using the same ellipsometer SER(R)S measurements of cy7.5 dye were performed using a uRaman 785 system (EiNST) where the excitation source wavelength was 785 nm A 20× Plan APO objective lens with NA = 0.75 (Nikon) was used to focus the laser beam Raman signals were collected under an excitation power = 0.5 mW All the SER(R)S spectra were subtracted from the dark spectra For Raman mapping of the samples and protein sensing a Renishaw InVia Raman upright microscope equipped with a 785 nm laser was employed This instrument was coupled with a Leica microscope and the laser light was focused onto the sample using an objective lens with a ×50 magnification and NA = 0.5 The scattered Raman signal was collected through the same lens and prominent Rayleigh scattering was blocked using a notch filter The beam spot size on the sample was carefully controlled to be approximately 2 µm to ensure high spatial resolution over 10 different areas were analyzed on each sample and 10 spectra were acquired from each area the laser was focused on the sample for 10 seconds and the Raman signal was integrated over the range of 600–1800 cm−1 The fluorescence background was subtracted using cubic spline interpolation and the instrument was calibrated using a standard silicon with its 520 cm−1 Raman peak Cy7.5 NHS ester (non-sulfonated) with an absorption maximum wavelength of 788 nm and emission peak wavelength of 808 nm was purchased from Lumiprobe Cyanine dye solutions with varying concentrations from 0.1 mM to 10 nM were prepared by serial dilution in DMSO solvent Samples were dipped in dye solutions for a short time and then performed the Raman measurements The absorption spectrum of the dye solution was determined using a UV-Vis Spectrophotometer 2-Iminothiolane hydrochloride (Traut’s reagent) (Sigma Aldrich) recombinant human cardiac Troponin I protein (cTnI) (Abcam) Anti-cardiac Troponin I antibody (Anti- cTnI) (Abcam) PE/Cy7® Conjugation Kit - Lightning-Link® (ab102903) (Abcam) bovine serum albumin (BSA) (Sigma Aldrich) ethanol (Merck) and phosphate-buffered saline (PBS) (Lonza) were purchased as indicated Commercial preparations of cTnI proteins and antibodies were used without modification To evaluate the performance of the fabricated substrate cyanine 7 (cy7) was utilized as the Raman-active molecule cTnI protein (Abcam) was treated with 14 mM Traut’s reagent and the resultant mixture was filtered using an Ultra-0.5 Centrifugal Filter Unit (Amicon) to eliminate excess reagent Lightning-link conjugation kit (Abcam) was used to conjugate the cy7 fluorescent probe onto the cTnI antibody and the mixture was incubated for a short time The resulting solution was filtered to remove excess unreacted reagents and the cy7-tagged antibody filtrate was reconstituted back to 0.1 mg/mL To confirm the specificity of our biosensing methodology we have performed a negative control in which we used another protein (matrix metalloprotein) instead of cTnI Based on the results we found that when non-cTnI protein is used the cy7-tagged anti-cTnI did not bind to the substrate and expressed a weak background signal which is lower than the lowest concentration of Troponin I tested All the reflection and transmission spectra were simulated using a transfer matrix-based simulation model written in MATLAB The finite difference time domain (FDTD) was used to simulate the electric field intensity distribution The commercially available Ansys Lumerical FDTD software was used for this purpose the periodic boundary condition was used along the x and y directions and a perfectly matched layer (PML) boundary condition was used along the z direction Experimentally determined spectral optical constants of Sb2S3 Further information on research design is available in the Nature Portfolio Reporting Summary linked to this article Data used in this study are available from the corresponding authors upon request. The experimental and simulation data are provided in the Source Data file. Source data are provided with this paper The codes used in this paper are available from the corresponding authors upon request Present and future of surface-enhanced Raman scattering Raman spectra of pyridine adsorbed at a silver electrode Surface raman spectroelectrochemistry: Part I and aliphatic amines adsorbed on the anodized silver electrode SERS of individual nanoparticles on a mirror: size does matter Surface enhanced Raman spectroscopy: benefits Development of highly reproducible nanogap SERS substrates: comparative performance analysis and its applications for glucose sensing Surface enhanced Raman spectroscopy for bioanalysis: reliability and challenges Surface enhanced Raman scattering in the ultraviolet spectral region: UV-SERS on rhodium and ruthenium electrodes Light-trapped nanocavities for ultraviolet surface-enhanced Raman scattering Ultraviolet nanoplasmonics: a demonstration of surface-enhanced Raman spectroscopy and Photodegradation using gallium nanoparticles Surface enhanced Raman spectroscopy with ultraviolet excitation Nanoimprint lithography of Al nanovoids for deep-UV SERS UV resonance Raman spectroscopy of the aromatic amino acids and myoglobin Surface enhanced resonance Raman spectroscopy (SERRS) for probing through plastic and tissue barriers using a handheld spectrometer Reproducible SERRS from structured gold surfaces Reproducible deep-UV SERRS on aluminum nanovoids Demonstration of a superior deep-UV surface-enhanced resonance Raman scattering (SERRS) substrate and single-base mutation detection in oligonucleotides Deep-UV surface-enhanced resonance Raman scattering of adenine on aluminum nanoparticle arrays Encyclopedia of Spectroscopy and Spectrometry (Second Edition) Surface Plasmons on Smooth and Rough Surfaces and on Gratings (Springer One-dimensional Tamm plasmons: spatial confinement Planar hot electron photodetection with Tamm plasmons Narrowband wavelength selective thermal emitters by confined Tamm plasmon polaritons Novel sensing concept based on optical Tamm plasmon Topological engineering of interfacial optical Tamm states for highly sensitive near-singular-phase optical detection Liquid-crystal active Tamm plasmon devices Observing and controlling a Tamm plasmon at the interface with a metasurface Deterministic inverse design of Tamm plasmon thermal emitters with multi-resonant control Wide bandgap phase change material tuned visible photonics Phase-change materials for non-volatile photonic applications Roadmap for phase change materials in photonics and beyond Chalcogenide phase change material for active terahertz photonics Electrically tunable all-PCM visible plasmonics Dynamic color generation with electrically tunable thin film optical coatings Electrical tuning of phase-change antennas and metasurfaces Electromagnetic Propagation in Periodic Stratified Media Electrically tunable steganographic nano-optical coatings Graphene–gold metasurface architectures for ultrasensitive plasmonic biosensing Phase change material-based low-loss visible frequency hyperbolic metamaterials for ultra-sensitive label-free biosensing Cardiac troponin level elevations not related to acute coronary syndromes The role of cardiac biomarkers in cardiovascular disease risk assessment Comparison of conventional and high-sensitivity troponin in patients with chest pain: a collaborative meta-analysis Extreme sensitivity biosensing platform based on hyperbolic metamaterials Biosensing with the singular phase of an ultrathin metal-dielectric nanophotonic cavity Optical antenna arrays on a fiber facet for in situ surface-enhanced Raman scattering detection Development of highly reproducible nanogap SERS substrates: comparative performance analysis and its application for glucose sensing Electrically reconfigurable nonvolatile metasurface using low-loss optical phase change material Ultra-low-energy programmable non-volatile silicon photonics based on phase-change materials with graphene heaters Electrically driven reprogrammable phase-change metasurface reaching 80% efficiency Broadband nanoscale surface enhanced Raman spectroscopy by multiresonant nanolaminate plasmonic nanocavities on vertical nanopillars Spectral analysis of multiplex Raman probe signatures Download references acknowledge funding support from the National Research Foundation Singapore under the CRP program (Grant No Technology and Research) under AME IRG Program (Grant No A2083c0058 and A20E5c0084) and HBMS IAF-PP (Grant No acknowledge the following A*STAR funding support: IAF-PP Grant H19H6a0025 and BMRC UIBR Grant acknowledges the funding support from the National Research Foundation Singapore (Award No.: NRF-CRP23-2019-0005) The authors also would like to thank Jodie Chua Zhi Tong for their help in SERS measurements Present address: A*STAR Skin Research Labs (A*SRL) Institute of Materials Research and Engineering (IMRE) School of Physical and Mathematical Sciences Patinharekandy Prabhathan & Ranjan Singh Centre for Disruptive Photonic Technologies initiated the tunable surface-enhanced Raman spectroscopy work performed spectroscopic and Raman measurements carried out calculations and numerical simulations All authors analyzed the data and discussed the results reviewer(s) for their contribution to the peer review of this work Download citation DOI: https://doi.org/10.1038/s41467-023-42854-7 Discover the insights you need to make better decisions today EY helps clients create long-term value for all stakeholders our services and solutions provide trust through assurance and help clients transform EY.ai - A unifying platform Technology transformation Tax function operations Climate change and sustainability services EY Ecosystems EY Nexus: business transformation platform Experienced professionals Student and entry level programs Talent community our purpose is building a better working world The insights and services we provide help to create long-term value for clients As cautious CEOs navigate trade wars and tariffs strategic leaders can use M&A as a long-term value driver Discover how shifts in demographics and tech reshape priorities urging new models for growth through innovative organizational strategies The sixth EY Climate Action Barometer shows an increase in companies reporting on climate but falling short of carbon ambitions Back to EY World Entrepreneur Of The Year™ Back to the Class of 2024 Jaanus Tamm’s entrepreneurial journey began as a university student with a passion for creating ground-breaking technology. His initial success, automating healthcare billing procedures, highlighted the power of determination. His resilience through multiple challenges, including setbacks in the Swedish market and the dot-com bubble bursting in 2000, established the foundation for DefSecIntel.  Founded in 2018, DefSecIntel designs advanced automated technologies, primarily for world-class border surveillance systems, that facilitate swift and efficient threat detection. These include AI-based surveillance systems for critical monitoring in hostile environments, as well as automated monitoring solutions and products for internal security and defense.   Jaanus wants to automate surveillance to create a safer world. DefSecIntel's world-class border surveillance systems play an important role in fighting cross-border crimes, smuggling and illegal border crossings. Looking ahead, Jaanus is using his visionary, optimistic leadership and tenacity to instigate change while striving to make DefSecIntel a globally preferred partner for border and military surveillance. EY refers to the global organization, and may refer to one or more, of the member firms of Ernst & Young Global Limited, each of which is a separate legal entity. Ernst & Young Global Limited, a UK company limited by guarantee, does not provide services to clients. the platform is designed to meet the evolving needs of citizens visitors and investors DGE is setting a new standard for digital governance with TAMM’s comprehensive one-stop shop (Photo Credit: WAM) Published: Wed 16 Oct 2024 DGE is setting a new benchmark in digital government through TAMM’s one-stop-shop featuring a unified app and portal, offering over 800 seamless services through a personalized, highly intuitive platform designed to meet the evolving needs of citizens, residents, visitors and investors. The Department of Government Enablement (DGE) has revealed TAMM 3.0 at Gitex Global 2024 an AI-driven platform that significantly enhances the delivery of government services in Abu Dhabi In partnership with various Abu Dhabi government entities DGE is setting a new standard for digital governance with TAMM’s comprehensive one-stop shop This platform provides over 800 seamless services tailored to meet the diverse needs of citizens and investors through a highly intuitive and personalized interface The launch of TAMM 3.0 aligns with the Abu Dhabi Government’s Digital Strategy and the UAE’s National AI Strategy 2031 driven by a vision to enrich the lives of all stakeholders by leveraging advanced technologies and innovation to improve public services The Chairman of the Department of Government Enablement highlighted that the introduction of TAMM 3.0 represents a crucial advancement in enhancing the delivery of government services in Abu Dhabi reflecting the leadership’s goals for seamless TAMM 3.0 is crafted to deliver a highly personalized experience for each user allowing users to engage through voice commands in both Arabic and English Read more: Gitex Global 2024: DCD Abu Dhabi launches Bayanat community platform to streamline reporting, enhance decision-making and its advanced algorithms analyze user behavior and preferences to tailor services and recommendations ensuring that every interaction is relevant and user-friendly—whether for renewing licenses TAMM 3.0 provides a wide array of AI-enabled government services consolidated into a single platform highlighting DGE’s commitment to delivering efficient and future-ready services to the people of Abu Dhabi TAMM Care has been significantly upgraded within TAMM 3.0 This upgrade ensures a superior customer experience it offers responsive and proactive support The support is powered by real-time dashboards and a Customer-360 view TAMM has expanded its Live Support services This allows customers to connect directly with a TAMM agent virtually They can also receive personalized assistance from the comfort of their homes It aims to transform the Product Delivery Life Cycle within TAMM The system utilizes AI in all phases: ideation Mohamed Al Askar emphasized the mission to challenge the status quo and enhance the experience and quality of life for citizens aligning with DGE’s vision for an AI-native government the AI Assistant of TAMM enables real-time contextualized responses to customer inquiries and applications the platform is poised for further evolution integrating new features and services that will continue to redefine the potential of digital governance the launch of TAMM 3.0 at Gitex 2024 marks a pivotal moment in Abu Dhabi’s journey It aims to establish the emirate as a global hub for innovation and technology-driven governance This initiative further solidifies Abu Dhabi’s status as a leader and pioneer in the field For more news on technology, click here. The national teams of Lithuania and Estonia played their first matches in the 2026 World Cup qualifiers Justas Lasickas’ home team initially suffered a minimal defeat in Poland where Robert Lewandowski scored in the final but yesterday the Lithuanian players came from 2-0 down to earn a point against Finland Alex Matthias Tamm initially lost to Israel with Estonia but today the Estonians defeated Moldova 2-3 The hot striker of the Dragons entered the game twice from the bench for the reserves (82′ and 66′) 25.04.2025 | The Dragons failed to make it to the cup semi-finals The match in Celje ended with a 2:1 victory for the home team 23.04.2025 | Countdown to the semi-final match of the Pivovarna Union Cup where the Dragons will attack their place in.. 22.04.2025 | the last eternal derby of the current season will be played in Stožice The match for the championship will start on Saturday Olimpija Ljubljana Football Club is one of the most successful Slovenian clubs We are committed to the development of football the upbringing of young talents and achieving top results in domestic and international competitions © FC Olimpija doo 2025. All rights reserved. / Designed by Jana Tavčar sp Metrics details Solid-state cavity quantum electrodynamics is a rapidly advancing field which explores the frontiers of light–matter coupling Metal-based approaches are of particular interest in this field as they carry the potential to squeeze optical modes to spaces significantly below the diffraction limit Transition metal dichalcogenides are ideally suited as the active material in cavity quantum electrodynamics as they interact strongly with light at the ultimate monolayer limit we implement a Tamm-plasmon-polariton structure and study the coupling to a monolayer of WSe2 Exciton-polariton formation at room temperature is manifested in the characteristic energy–momentum dispersion relation studied in photoluminescence featuring an anti-crossing between the exciton and photon modes with a Rabi-splitting of 23.5 meV Creating polaritonic quasiparticles in monolithic compact architectures with atomic monolayers under ambient conditions is a crucial step towards the exploration of nonlinearities macroscopic coherence and advanced spinor physics with novel suggesting their suitability for room-temperature polaritonics strong coupling has been demonstrated in WSe2 monolayers We map out the characteristic energy–momentum dispersion relations of the upper and the lower polariton branch at ambient conditions by angle-resolved PL and reflection measurements Our experimental findings are supported by modelling our device in a coupled oscillator framework showing an excellent agreement between theory and experiment (a) Schematic illustration of the Tamm-plasmon device with the embedded WSe2 monolayer whose thickness primarily determines the frequency of the device’s optical resonance (b) PL spectrum of the WSe2 monolayer before capping The dominant emission is identified to stem from the A-valley exciton Inset: false-colour optical microscopy image of the used WSe2 flake (monolayer in red shaded area; scale bar (c) Calculation of the electromagnetic field intensity in the heterostructure and the optical resonance (inset) The Tamm-plasmon features a strongly enhanced field maximum close to the surface of the structure which coincides with the vertical position of the monolayer in the device The optical resonance features a quality factor on the order of 110 (a) PL spectra recorded from the coupled device at room temperature at various in-plane momenta (depicted in a waterfall representation) Two pronounced resonances evolve in the system which feature the characteristic anti-crossing behaviour of exciton-polaritons (b) Energy–momentum dispersion relation of the lower and upper polariton branch at room temperature: the polariton energies are extracted by fitting spectra at various in-plane momenta (solid symbols) A coupled oscillator approach is employed to fit the data and to demonstrate excellent agreement between experiment and theory (lines) (c) Plot of the exciton and photon fraction of the lower polariton branch as a function of the in-plane momentum extracted from coupled oscillator fit (d) Inverted reflectivity spectra at different in-plane momenta (e) Energy–momentum dispersion relation extracted from the reflectivity spectra we can fit the dispersions with a coupled oscillator model: where Eph and Eex are photon and exciton energies and Γph and Γex are photon and exciton mode broadening The eigenvectors represent the weighting coefficients of exciton and photon fraction and ħΩ represents the Rabi splitting in the system (a) Room-temperature false colour intensity profile of the full polariton dispersion relation extracted from the PL measurements (b) Model of the full dispersion by assuming a Boltzmann distribution of the quasiparticles with an effective temperature of 300 K where Γph is the broadening of the photonic mode and the i-index spans over the two polariton branches. We extract the value of Γph=15 meV from the experimental data. The experimental results and the theoretically calculated dispersion relation are plotted in Fig. 3a,b nonlinear optical circuits and logic devices which are operated at ultra-low powers and close to terahertz frequencies The sample was designed based on transfer matrix calculations where the plasmon-polariton resonance was tuned to match the A exciton resonance of WSe2 monolayer at room temperature (1.650 eV) The bottom mirror consists of a commercially available DBR based on a fused silica substrate topped with ten pairs of TiO2/SiO2 layers (72/117 nm thickness corresponding to a central stopband wavelength of 680 nm) The WSe2 monolayer was mechanically exfoliated onto a polymer gel film (polydimethylsiloxane) and was then transferred onto the bottom DBR One hundred and thirty nanometres of PMMA were deposited by spin coating onto the structure a 35 nm-thick gold layer was thermally evaporated onto the sample We took advantage of an optical setup in which both spatially (near-field) and momentum-space (far-field)-resolved spectroscopy and imaging are accessible PL is collected through a 0.7 numerical aperture microscope objective lens and directed into an imaging spectrometer with 1,200 groves mm−1 grating via a set of relay lenses projecting the proper projection plane onto the monochromator’s entrance slit The system’s angular resolution is ∼0.05 μm−1 (∼0.5°) and spectral resolution is ∼0.050 meV with a nitrogen-cooled Si-CCD as detector As the fine spectrometer grating (1,200 groves mm−1) does not cover the full spectral range of the PL signal the angle-resolved PL spectra were taken at three different energies with ∼60% overlap and were subsequently combined This procedure used a fast Fourier transform (FFT) smoothing algorithm to account for small-intensity offsets in the overlap regions single spectra were fitted with a two-Gaussian fit The data that support the findings of this study are available from the corresponding author upon request Room-temperature Tamm-Plasmon exciton-polaritons with a WSe2 monolayer Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Two-dimensional transition-metal dichalcogenide materials: toward an age of atomic-scale photonics Exciton binding energy and nonhydrogenic Rydberg series in monolayer WS2 Electronics and optoelectronics of two-dimensional transition metal dichalcogenides Photoluminescence emission and raman response of MoS2 Giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor Spin and pseudospins in layered transition metal dichalcogenides Polarization and time-resolved photoluminescence spectroscopy of excitons in MoSe2 monolayers Double resonant Raman scattering and valley coherence generation in monolayer WSe2 Valley Zeeman effect in elementary optical excitations of monolayer WSe2 Observation of the coupled exciton-photon mode splitting in a semiconductor quantum microcavity Collective fluid dynamics of a polariton condensate in a semiconductor microcavity Strong light—matter coupling in two-dimensional atomic crystals Exciton-polaritons in van der Waals heterostructures embedded in tunable microcavities Spin-orbit engineering in transition metal dichalcogenide alloy monolayers Effect of longitudinal excitations on surface plasmons Emission of Tamm plasmon/exciton polaritons Electro optical tuning of Tamm-plasmon exciton-polaritons Tailoring the optical properties of wide-bandgap based microcavities via metal films Monolayered MoSe2: A candidate for room temperature polaritonics Angle-resonant stimulated polariton amplifier Exciton-polaritons in 2D dichalcogenide layers placed in a planar microcavity: tuneable interaction between two Bose-Einstein condensates Surface Plasmon Nanophotonics Springer (2007) Download references This work has been supported by the State of Bavaria Tongay for providing initial samples for the project Kim for assistance in the exfoliation and pre-characterization of the high-quality monolayer material Brodbeck for assistance with the transfer matrix calculations Worschech for encouraging him at the very early stage of the work acknowledge the partial financial support from the EPSRC Hybrid Polaritonics Programme acknowledges financial support by the European Research Council (unLiMIt-2D project) Technische Physik and Wilhelm-Conrad-Röntgen Research Center for Complex Material Systems analysed and interpreted the experimental data The authors declare no competing financial interests Supplementary Notes 1-6 and Supplementary References (PDF 888 kb) Reprints and permissions Download citation Time Out Abu Dhabi Sign up to our newsletter for the latest and greatest from your city and beyond Home » News » Your TAMM app just got a serious upgrade Listen up Abu Dhabians because the TAMM app has just dropped its biggest update yet and it’s about to change how you handle government services (think ChatGPT version 3.0 is an AI-powered upgrade that answers all your burning questions in real time The previous update already made life easier by giving you access to over 700 services across 33 government entities (seriously with new perks designed specifically for investors and entrepreneurs who can now access services related to energy As part of the Abu Dhabi Government pavilion at @GITEX_GLOBAL, government entities across the emirate have launched, on the fourth day of the show, new initiatives that support the adoption of innovative solutions to serve the community. pic.twitter.com/og6bXEttzM If you haven’t been introduced to the TAMM app already – or you just need a little refresher – it’s essentially your all-in-one digital gateway to government services in Abu Dhabi whether you need help with identity documents They even recently added a credit report service that allows users to view their credit scores directly on the app You can pretty much consider it your 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TAMM is part of Abu Dhabi’s sustainability push by digitising services and reducing the need for physical documents TAMM Abu Dhabi’s census shows just how much the emirate has changed in a decadeWe may be biased Revealed: top 10 things UAE residents like to do in their spare timeCan you guess 22 brilliant beach and pool day passes in Abu DhabiVisit these spots to cool off Whether it’s a working lunch or a midweek treat An exceptional café where desserts are as dramatic as they are delicious A hidden jazz bar made specifically for dessert-lovers Lebanese-leaning seafood spot with views of the sea Unexpected spot that serves up the best Vietnamese bowls in the city Subscribe to Time Out Abu Dhabi’s newsletter to get expert FRONTLINE reports from Iraq on the miscalculations and mistakes behind the brutal rise of ISIS WATCH » ISIS' growing foothold in Afghanistan is captured on film WATCH » Former Department of Justice attorney Thomas Tamm uncovered evidence of the government's secret electronic surveillance of U.S a discovery he later leaked to The New York Times He spoke to FRONTLINE's Jim Gilmore on Dec describe for us the job you had at OIPR [Office of Intelligence Policy and Review] from 2003 your responsibilities there and how you found your way into that position I found my way into that position after 9/11 I was working for the Capital Case Unit in the Department of Justice and doing death penalty litigation we met with the victims' families up in New York and the Pentagon I felt really motivated to try and go more directly after the people who had attacked our country so I applied for a position with what was then called the Office of Intelligence Policy and Review where I kind of was led to believe that you would work with agents to try and develop intelligence about people that we thought were foreign agents or terrorists So I went in with a lot of patriotic fervor it actually ended up being much more of a word-processing job and it really wasn't working with agents to kind of develop cases because it was almost like an assembly line a factory assembly line of trying to get out these FISA warrants and trying to get as many FISA warrants Foreign Intelligence Surveillance Act warrants There was always pressure to get more and more wiretaps authorized by the court So the job really wasn't as much about developing leads and developing cases as it was just more trying to go up on people I mean wiretap their phones or their electronic surveillance there was a fairly short period of training and you learn that because of abuses by the FBI and J Edgar Hoover's tenure that the Church Committee in 1978 had come up with legislation to try and rein in the executive and try and protect the privacy of U.S citizens and Americans more so than had been in the '70s So our role was to present applications for wiretaps to a court that was specially formed as a result of the Church Committee called the Foreign Intelligence Surveillance Court we would regularly appear before the FISA Court and seek applications to wiretap So you were sort of the connection between the FISA Court and the DOJ [Department of Justice] Absolutely essential point for any investigation to go forward in a world where warrants were absolutely necessary if you were going to do any domestic wiretapping that it was absolutely essential to go through that court the legislation said that it was the exclusive means by which we would conduct electronic surveillance of these people and the law specifically said that if you didn't go through the court the Church Committee in their wisdom had really set up the intelligence committees in the House and the Senate and also this FISA Court to help with checks and balances in a world which is otherwise pretty impossible to understand what's going on It's just the government appearing in front of a judge There's no defense attorney arguing: "Wait a second You don't have probable cause." So I think it was incumbent with really a lot of power and a lot of secrecy to try to be totally ethical about what we were doing a little bit about your bio and how long-serving your family has been in this world my father was an assistant director of the FBI I remember as a young child watching John F served an entire career as a special agent in the FBI And my father's brother was also an assistant director of the FBI and then was appointed to the federal courts and became a U.S I was a prosecutor in the state's Attorney's Office prosecuting crimes of violence and then joined the United States Department of Justice with the Capital Case Unit So you at some point stumble upon the existence of the NSA program was that an FBI agent would come across the street that came from someone caught on the battlefields in Afghanistan and they had phone numbers and links back to the United States and we would develop hopefully enough information for probable cause to believe that person was connected with a foreign agent or a terrorist group there was a certain subsection of cases that were "in the program," and every warrant that you reviewed as a lawyer I always thought that was kind of Kafkaesque to refer to it that way Only the attorney general could sign those applications for warrants The deputy attorney general who was nominated by the president and approved by the Senate was not "read into the program." He couldn't sign those warrants Out of all of the judges who all had top-secret security clearances who obviously were federal judges only one judge could sign these warrants that were "in the program" and I asked a supervisor of mine if she knew what the program was about She told me that she just assumed that what we were doing was illegal and she didn't want to ask any questions That really ate away at me and bothered me because I thought I had gone into law enforcement to enforce the law who I admired and I think is a very able lawyer and is ethical as well telling us that if we ever were reluctant -- we had to sign the warrants as well and these affidavits -- that if we were ever reluctant to put our names on these warrants to bring it to him and he would sign them I just was looking at these documents and couldn't figure out what would be in there that I would not want to put my name on that piece of paper and basically swear to the court as to its veracity and authenticity that this file I'm handing you right now includes an "in the program" document or affidavit That was another thing that kind of was bothersome It was clear we weren't meant to know what it meant But the very first time you were given an application for a warrant it was incumbent upon the lawyer to go to one person in that office who was connected to the NSA And he was the only person who was connected to the NSA and he had secret computers to be able to communicate with the NSA is that number in the program?" And we would wait a couple of days it's not in the program." So you knew that you could get the deputy attorney general you could get all these other people to sign these documents it is in the program," then it took this peculiar track and there were only about maybe 5 percent or 10 percent of the cases were "in the program." And it just ate away at me and came to a head when I ran into one of the deputies of the unit who said that the program had been shut down that some information from the program had gotten into a regular FISA warrant that there was a chance that for the first time ever that a sitting attorney general would be indicted and a sitting attorney general is going to be indicted that I didn't want to keep participating in whatever was going on The thing you did know about the program and these affidavits is that they were connected to the NSA What were the conversations around the water cooler But it was my understanding that the NSA only conducted the surveillance and electronic surveillance overseas that they were not tasked with doing anything in the United States the FISA Court and the FISA Department of Justice were the ones that were tasked with doing any surveillance domestically I didn’t think much of it other than it was so strange to me that somebody who was the deputy attorney general of the United States could not review these particular affidavits So one of the things you do know about the program is that Larry Thompson And you have to remember that we had also started bombing Iraq and the place where I worked really was almost at a fever pitch everybody was just -- that fear permeated that office suite But if we would get an application that was in the program and the attorney general of the United States was in Missouri we had to get on a plane and fly to Missouri to get him to sign those documents We had to go wherever he was traveling as opposed to you can go to the deputy attorney general or you can go to the director of the CIA it was just one person that we understood had been "read into the program." And who was instructing you on what could or could not be done The head of the Office of Intelligence Policy and Review So you go talk to OIPR counsel Mark Bradley at some point and he tells you that the judge that you're bringing this to over at the FISA Court is objecting to some of the issues about this Mark Bradley was one of the two deputies of the Office of Intelligence Policy and Review and there was just kind of a buzz throughout the office but it was clear that something fairly major had happened and he said that something from the program had gotten into a regular FISA application that the chief judge of the FISA Court was -- I can't really say what word I remember him using She was very upset that something from this program had gotten into an affidavit that had gone to just one of the normal regular FISA judges And that was when he told me that he thought a sitting attorney general might be indicted for the first time in our history what do you think was really going on here It is right around the time that from the timeline or chronologically Larry Thompson had left around that time and the new deputy attorney general was a fellow named Jim Comey He had a background somewhat similar to mine He had done a lot of law enforcement-type; that was his background he insisted on being read into the program we've since come to learn that he quickly recognized that what was being done was illegal and that is when the famous scene occurred when he rushed over to the George Washington Hospital where the attorney general was severely ill because he had heard that I guess it's Alberto Gonzales and someone else from the administration from the White House was going over for authorization to continue doing this programming I would think that all has to be interrelated as to the possible misrepresentations the reason the FISA chief judge was so upset and the fact that Mr Comey clearly believed that what we had been doing was not authorized by the law this was the chief justice over at the FISA Court was this the same judge that you guys had been bringing the affidavits to all along You would bring it over to her office; she would take a look at it because she was stationed here in Washington we wouldn't necessarily see her in the FISA Court which at the time was in the Department of Justice in a bank vault on the sixth floor But if it was a case that was in the program that's where she just poured over the document and checked everything She would ask questions of the attorney and for clarification and you had to be really prepared with regard to what was in that affidavit that you were submitting to her it becomes clear that the problem here is that the reason for the worry about that the information from the program getting into these other affidavits is because the material that was gathered must have been considered possibly illegal I knew that if a search warrant was issued but that it was based on false information or based on evidence that had been gathered illegally that it jeopardized your entire case against someone the prosecution of a really significant target I think it's now clear that they were conducting electronic surveillance without getting warrants and using that information then to develop probable cause and basically not informing the court of the source of the information it could really damage the government's ability to bring somebody to justice So I know you don't know about what's going on with Comey over at Ashcroft's hospital room But what happens to the program immediately afterward the word was from this deputy of the office was that the program had been "shut down" and that you would no longer and you would not have to check with the person in the office that was in touch with the NSA to see whether the number was in the program because it "had been shut down." So it was right around the time that I had decided to leave that office because I was not comfortable working in that with my thought that there was something illegal going on So that was the ramification: "The program has been shut down." And then I believe I heard shortly before I left that it was back up and running as the line lawyers would have to check with the person with the NSA to make sure that if it was in the program So what period of time was there in between when it was shut down and when it restarted I think my recollection is it was about two or three weeks And you had left within that period of two or three weeks and then what are you guys told about it starting up again That we should continue to determine whether the number or the email address or what they call the facility was in the program Comey had now been read into this program so he would be authorized to sign affidavits or FISA applications that were in the program You at some point raise the issue with Sandra Wilkinson at the Senate Judiciary Committee I was very concerned about what was being done and whether the Congress knew what was being done just kind of going back to law school and civics classes and learning about checks and balances and what I thought were supposed to be three coequal branches of government I decided to go reach out to somebody who I knew on the Hill I had worked on a death penalty case with I knew she would have a top-secret security clearance So I went to get a cup of coffee with this person and I basically laid out what I've been talking to you about with regard to this separate track "Can you please talk to someone on Intelligence and find out whether Congress knows what is being done?" And if Congress knows and they've been briefed and they understand what is being done then I would just walk away and be satisfied with that So I had a fairly long meeting with her and left and never heard back from her for several months I was still with the Department of Justice and I used my government computer email to reach out to her again and say "Can we have another cup of coffee?" And I went back up on the Hill and met with her Does Congress know what we're doing with regard to this program?" And she said she couldn't tell me and that she just -- and I said then I think maybe I will go to the press," whistleblowers frequently don't end up very well." And I told her the fact that it was so closely held that only literally what I thought two lawyers in the Department of Justice knew what was being done It had not been vetted by various layers of lawyers and all that sort of thing And all of the comments about "I assume what we're doing is illegal," and "The attorney general is going to get indicted," and "I'll sign it if you don't want to sign it." I just put everything together and felt that -- and again the fact that we were rendering people to states that we knew tortured them I just decided to -- I had read articles by Eric Lichtblau with The New York Times I knew he was covering the Department of Justice and I felt like he had a pretty good handle of what was going on in the department So what did it take you to go to that subway station and find that phone and how did you come to that decision and that phone Take us to that moment where you go over to that phone and you put -- I don't know how you use a telephone anymore Do you put a dime or a quarter or whatever the hell you put into it cell phones weren't as ubiquitous as they are now It's difficult to even think back to that time and remember what I was thinking there was drip by drip in the national press with regard to things that seemed to be somewhat haywire with regard to following the law and I thought that maybe the trains going by would mask the conversation or whatever but how would they know who was using that particular pay phone I'm sure I could have just called him straight up And it may have been a little bit of stupidity I certainly was conscious of the fact that if I were going to be found out -- and I did think I would be found out actually eventually -- that there would be serious ramifications with what I thought was being done to the way our government was supposed to work Lichtblau who covered the Department of Justice I said that I thought I might have some information that might be of interest to him and I probably said that it would be with regard to foreign intelligence I did a little probably ridiculous song and dance of just getting to know him and not really disclosing anything at the first meeting and he assured me that he would never reveal his sources It was also around the time that another reporter was running into problems about revealing sources He was very interested in whatever it was that I had to offer I don't think I even really told him where I worked the first time kind of tried to assess his character and see whether I thought that this was going to be worth it and then finally I showed him my credentials from the Department of Justice and told him where I had worked and what my concerns were pretty immediately said that there was another -- he had a colleague named James Risen but he had a colleague who had sources in the NSA and the CIA and they were hearing the same sort of thing But they did not have a source in the Department of Justice and they weren't sure what was being done with the information that they were learning about from the NSA and the CIA sources and that I could potentially be the link to explain what was being done with that It got to the point where he would come back and say and we're hearing that they are gathering electronic surveillance without going through the FISA Court," and did I think that that would be legal This is the only way that you're supposed to conduct electronic surveillance of this type." So I eventually told him basically what I've been saying here with regard to my suspicions very limited people knew what it was all about and that really some very experienced high-level lawyers thought what the government was doing was illegal … Explain what you thought the consequences might be and if you second-guessed yourself I did think there was a real chance that I would be prosecuted and I actually even got to the point where I wondered whether I'd be out on bond or whether the bond would be so high that I wouldn't be able to make the bond so I didn't look forward to that possibility And I had worked in the death penalty area and if someone reveals what's called signals intelligence secrets there is potentially a death penalty possibility that the government could seek a death penalty I didn't think what I was revealing rose to that level but I was concerned that someone would say because we're gathering these through electronic intercepts," and that sort of thing I didn't think that was much of a realistic possibility but I did feel if it was ever published that eventually the government would subpoena the reporters that they would try and exercise their right not to reveal their confidential sources and that would be litigated and that they would eventually be ordered to turn over their sources So I did think that I would eventually be found out Looking back at a timeline and referring to articles that have been written about it it was in the fall of I guess 2004 that they had the story Risen met with me and said they felt they had a really good story and they said they had these other sources and they thought it was going to be a really important story to run I remember having lunch with them after a year had passed and Jim Risen said that the story was going to run that the White House had said that The New York Times would have blood on their hands And they kind of asked my opinion about that "I don’t understand that." I said: "It's public knowledge we wiretap people by getting authorization to do that How does it jeopardize anything for them to know that we wiretap people without getting authorization and without a piece of paper?" Mr. Risen said that he was writing a book and that he had basically said to the publisher that he was going to publish this story in his book if they did not run the story. And that is when the story ran You start getting phone calls from the FBI soon after What's it like to have the FBI starting to call you I don't know whether he came by my office -- I was still with the Department of Justice in a different unit -- and I told him that I chose not to talk to him I chose to exercise my rights under the Constitution to not be a witness against myself I knew that immediately would send up red flags and I would immediately be their primary suspect and went in and talked to him and realized that I needed a lawyer So you're getting deeper and deeper in trouble here and I'm not sure I was -- I know I wasn't doing the greatest job in the world I was preoccupied with what was going to happen to me and when it was going to happen and what was going to happen the FBI is a part of the Department of Justice and I've told them that I'm not going to talk to them that I shouldn't stay an employee of the Department of Justice So it certainly was somewhat -- it was a mutual decision that we parted ways Take us to that day and what that was like and what you were thinking I had left that day to take my son to a summer school class and also had a doctor's appointment to get a second opinion on orthopedic surgery and I remember driving in my suburban residential neighborhood and noticing that there were a line of cars parked at one side of the street My first thought was that somebody was having a party and I hadn't been invited and then I looked over kind of more in the middle of the street and she was trembling and crying and asking what was going to happen to us the agents were coming in and out of the house carrying boxes of stuff and wearing their blue jackets with the big yellow FBI on the back had been on raids or search warrants and knew kind of the technique of being assigned of which room to go to and my wife was confronted by these people some of whom -- and the neighbors said -- had guns drawn knocking on our door and demanding to see her hands and shouting at her and then she had to reach for the keys because we have window panes on the side of the door I've learned that they rushed into the house and two of them woke up two of my children in bed They were awakened by strangers wearing guns They were all brought down to the first level and kind of gathered in one spot and then they were asked questions about whether I had come into unusual amounts of money whether any New York Times reporters had ever been to our house whether there were any secret compartments in our house A lot of records were taken out of the house Actually missed a couple of old cell phones It never occurred to me that they would hit my house I thought it would go through a grand jury process with the reporters Lichtblau that when it got to that point that he did not have to go to jail for me; he could reveal his source So the raid on my house was unquestionably one of the worst days of my life and he told me that he had been contacted by the Department of Justice I could plea to -- I think it was going to be espionage and it was contemplated -- the maximum penalty but it would be contemplated under the federal sentencing guidelines that I would go to jail for a period of time so I'm not interested." And I think that undoubtedly surprised the Department of Justice I don't remember whether it was before or immediately after hearing that they were offering me a plea but I got a phone call from [investigative journalist] Mike Isikoff I recognized his name from reading Newsweek He knew that I had had disagreements with the administration over death penalty prosecution He knew what had been taken out of my house And I'm thinking at least I knew there was more than one leak in the Department of Justice But I told him I really couldn't talk to him at that time and that really is the time then that I became aware -- I heard from people that the FBI had been at the old prosecutor’s office They knew who I had lunch with at times; they knew I wasn't going to an office function and just really became aware that obviously I was under fairly significant surveillance Is there a hope that at some point the new administration might bring relief to some extent and I had a lot of hope for hope and change but I actually thought that somebody might say and we'd like to offer you a job again in the Department of Justice." I would not have gone back to the intelligence side; I would have gone back to working on death penalty cases where I was more comfortable and that was really kind of my career background I actually kind of figured that after the election that I would get indicted between the election and the inauguration and I guess it was around that time that I decided to be -- basically had a really good handle and obviously had sources that knew what had happened and I had started during that period of time to meet with him somewhat similar to my meeting with Eric Lichtblau over a series of meetings and started talking to him with the understanding that he would not write anything until I gave him authorization to write something my view of what it was was I thought I would lay everything out: Here's what I did It just got to the point where I just felt like it made sense to try and be proactive rather than just sit around and take punch after punch after punch Well, I ended up talking to or authorizing Mike Isikoff to write a story about what I had done, told him much of what I'm saying here today. ... I don't really remember when that story was published, but it came out That actually lifted a sizable weight off my shoulders and they asked me to appear in front of a grand jury that was convened or sitting in the Eastern District of Virginia I was given immunity for whatever I said in there in terms of prosecution couldn't be prosecuted for what I said before the grand jury It was my understanding that it was part of this investigation that still seems to be ongoing about Jim Risen and leaks from the CIA and/or the NSA And I was told that I would only be asked questions about a very limited part of his book And when I went in there to the grand jury and the lawyer from the Department of Justice comes out and talks to Mr and says that it's over; there are not going to be any charges And I remember contacting my wife Claire and saying that there are not going to be any charges And she said "Well will they put that in writing?" And I said "Hey Paul will they put this in writing?" And he said "No they do that for upper-level people in the departments seizures of my Christmas card list and computers and cell phones and an offer to plead guilty I'll take the plea," hoping that I get less time than if they end up trying me My biggest regret is what I put my family through I hope my father would be proud of what I did I know he was upset that the FBI's reputation was kind of besmirched by their wiretaps of Martin Luther King and John Lennon he was certainly anything but -- he was not a raging liberal But I really hope that he would be proud of what I did One of the things that the NSA and the White House said was the FISA system was broken It was too slow; it couldn't get the intelligence that they needed to prevent the next attack Did it seem like the FISA system was broken That's one aspect of this story that I was really bothered by in real time as it was kind of going on was the argument that we wouldn't be able to get the ticking-time-bomb person and that the process was too slow and broken The fact is we regularly got emergency authorizations for FISA and the statute specifically provided for an emergency -- that you could start tapping before you actually went to the court You could start gathering intelligence before getting authorization by the court if you put in the document probable cause within 72 hours after you had started it was that if a judge said that you did not have probable cause you then had to tell the person whose communications had been overheard or who'd been seized But that's one of the things that really bothers me about the whole aspect of the case is that the people who were the subjects of these warrantless wiretaps The law provides that in emergency situations if it isn't found to be validated by the court that we're going to find that there were enemies lists potentially that we're going to find some people will really be surprised their phones were wiretapped That’s a really bothersome aspect of the story But back then it was literally in a bank vault because they were worried about the Soviet Union overhearing what was going on I think they probably have fingerprint analysis the thing that you put your finger on now to get in In order to foster a civil and literate discussion that respects all participants FRONTLINE has the following guidelines for commentary you are consenting to these rules:Readers' comments that include profanity Entries that are unsigned or are "signed" by someone other than the actual author will be removed We reserve the right to not post comments that are more than 400 words We will take steps to block users who repeatedly violate our commenting rules You are fully responsible for your comments Metrics details We put forward the concept of high-order Tamm plasmon (TP) modes which are illustrated with a simple metal-Bragg mirror cavity Results show series orders of TP modes are gradually generated through adjusting the thickness of the cavity for which traditional TP modes only corresponds to the zero-order modes The reflectance spectra and electric field distributions are compared to demonstrate the consistency of these series of TP modes the excitation intensity of different order TP modes are studied Results show that the excitation intensity is related directly to the TP mode wavelength These results might provide new ideas to the study of TP modes and guide the design and optimization of TP based devices we put forward the concept of high-order TP modes we theoretically studied TP modes with a simple cavity consisted with metal film and Bragg mirror which also can be called as metal-Bragg mirror cavity Results show that TP modes have many different orders when we increased the thickness of the cavity while only the zero-order TP modes has been widely studied The consistency in physical mechanism behind TP modes in different orders is discussed referring to the reflectance spectra and the electric field distribution These results might greatly expand the study and application of TP modes (a) Schematic of the extended Tamm structure (b) Reflectance spectrum of the proposed structure The dotted line is the reflectance spectrum of bare Bragg mirror (c) Electric field distribution of the proposed structure at TP mode tk and rk are the transmission and reflection coefficients of light transmitting from the (k − 1)-th layer to the k-th layer φk is the phase of light propagating in the k-th layer The total transfer matrix of the proposed structure can be deduced as Ti and Pi refer the transmission matrix and propagation matrix for the interlayer Ts and Ps refer the transmission matrix and propagation matrix for the silver film The thickness of silver film is thick enough that the transmission light of the proposed structure is approximate to zero Thus the reflectance and absorptance of the proposed structure can be expressed as R = |M21/M11|2 and A = 1 − R It can be found that field enhancement appears near the interface of silver film and Bragg mirror The main characteristics of TP mode are the narrow valley of reflectance spectrum in the stop-band of Bragg mirror and the electric field enhancement the above results demonstrate the traditional Tamm structure without interlayer can excite TP mode here, rBR is the reflection coefficient of the light incident from the interlayer to the Bragg mirror and rS is the reflection coefficient of the light incident from the interlayer to the silver film. i refers the imaginary unit. φi = 2πnidi/λ is the phase of light propagating in the interlayer. We can rewrite Eq. (3) in the form we can obtain that Tamm mode at a certain wavelength can be excited in series of orders To demonstrate the consistency between different orders of TP modes we investigate the spectra and the electric field distribution of these TP modes (a) Reflectance spectra of the extended Tamm structure at different thickness of interlayer (di) (b) Optical field distribution of the extended Tamm structure at 1.8204 eV when di = 10 nm (a) Reflectance spectra of the extended Tamm structure at different thickness of interlayer (first-order TP mode) (b) Optical field distribution of the extended Tamm structure at 1.8204 eV when di = 350.6 nm (c) Reflectance spectra of the extended Tamm structure at different thickness of interlayer (second-order TP mode) (d) Optical field distribution of the extended Tamm structure at 1.8204 eV when di = 691.2 nm we can find the electric field distributions in the Bragg mirror the silver film and the 10 nm thick interlayer close to the silver are basically identical for different orders The electric field periodically repeats in the other part of the interlayer and the period number is consistent with m Reflectance spectrum for the proposed structure with different di (a) Reflectance spectra of TP mode at 1.9824 eV for different orders The subgraph is the reflectance spectra near 1.9824 eV (b) Dependence of valley value on valley position for TP mode The phase variation induced by the reflection on the silver film and the Bragg mirror (φr) remains unchanged when the thickness of interlayer increases But the light wavelength will have a stronger influence on the phase of light propagating in the interlayer (φi) when the thickness of interlayer increases Thus the sum of φr and φi for higher order TP mode will have more deviation from 2mπ when the light wavelength changes the TP mode valleys become narrower when the order (m) increases The structure will have higher sensitivity on the interlayer thickness if the TP mode valley becomes narrower That means high-order TP modes will have greater potential in optical sensors Through investing the excitation conditions we find series of TP modes can generate at suitable conditions All of the different order TP modes have narrow valleys in the reflectance spectra which is a greatly important property for TP modes electric field distributions of different order TP modes are basically identical in the Bragg mirror the 10 nm thick interlayer close to the silver and periodically repeats in the other part of the interlayer These results show the consistency of the different order TP modes the excitation intensity of different order TP modes are investigated with the valley value and FWHM Results show that high-order TP modes have the same valley value with zero-order TP modes but has narrower FWHM than zero-order TP modes It is well known that the optical properties of TP structures are dramatically influenced by the nearest layer to the metal film and most applications of TP modes are based on this nearest layer the thickness of this nearest layer is limited for the traditional zero-order TP modes which highly restricts its potential for large size applications such as detection of biological tissues and microfluids high-order TP modes have more excellent optical properties in the spectrum The use of high-order TP modes will provide new application fields to TP modes and optimize the design of TP based devices The datasets generated or analyzed during the current study are available from the corresponding authors on reasonable request Optical Tamm states for the fabrication of polariton lasers Tamm plasmon polaritons: Possible electromagnetic states at the interface of a metal and dielectric Bragg mirror Optical Tamm states above the bulk plasma frequency at a Bragg stack/metal interface Optical Tamm state enhanced broad-band absorption of organic solar cells High sensitive sensors of fluid detection based on magneto-optical optical Tamm state Confined Tamm plasmon optical states coupled to a photoconductive detector A Tamm plasmon-porous GaN distributed Bragg reflector cavity Enhanced nonlinear optical effects due to the excitation of optical Tamm plasmon polaritons in one-dimensional photonic crystal structures Tunable dual-band mid-infrared absorber based on the coupling of a graphene surface plasmon polariton and Tamm phonon-polariton Tamm plasmons for efficient interaction of telecom wavelength photons and quantum dots Telecommunication wavelength confined Tamm plasmon structures containing InAs/GaAs quantum dot emitters at room temperature Room-temperature lasing in a low-loss Tamm plasmon cavity Tunable perfect absorber supported by accumulation electron gas at ITO-dielectric heterointerface Tunable and multichannel terahertz perfect absorber due to Tamm surface plasmons with graphene Tunable high-efficiency light absorption of monolayer graphene via Tamm plasmon polaritons Electrically tuning reflection of graphene-based Tamm plasmon polariton structures at 1550 nm Generation and spatial control of hybrid Tamm plasmon/surface plasmon modes Liquid-crystal active Tamm-plasmon devices Tunable Tamm plasmon polaritons and perfect absorption in a metal-PC cavity Multiple optical Tamm states at a metal-dielectric mirror interface Multiple adjustable optical Tamm states in one-dimensional photonic quasicrystals with predesigned bandgaps Download references This work was supported by National Natural Science Foundation of China (No 12004217) and Natural Science Foundation of Shandong Province (Nos School of Physics and Optoelectronic Engineering Download citation DOI: https://doi.org/10.1038/s41598-022-19435-7 is hoping to join established Estonian players Denis Grabe and Mark Mägi at the peak of the game  After securing third place at the Estonian Championships the youngster is joining the prestigious Predator team alongside his compatriot and world number two Grabe Tamm took his third place in the domestic championships in the 9-ball format a competition featuring Estonia's top players His impressive performance at such a young age has made waves in the pool community both at home and abroad Tamm trains at the Predator Billiards Sports Academy most days His commitment to improvement was recently recognized when he became the second Estonian "This gives me even more confidence that this is the right path I want to invest even more in this and go further Train more and give my absolute best in every tournament," he said of his success Tamm's outstanding work ethic played a key role in his inclusion in the Predator team "Looking at the players on the Predator team yet not too many succeed in getting accepted it wasn't just his third-place finish in the Estonian championships which is of course an impressive enough achievement for a 15-year-old which I was able to convey to the Predator representatives he won't stop until he reaches the very top." Even more remarkable is that Tamm has only been playing for around five years "I got into this sport very much by chance I needed to find a new sport and thought I'd try pool But I went to the camp and got to try it out for the first time Follow ERR News on Facebook and Twitter and never miss an update! 0)" class="article-poll-disclaimer" ng-bind="totalVotes + ' hääletajat'"> {{option.votes}} {{selectedLanguage.poll.votes}}/ Iga kasutaja võib hääletada {{poll.optionLimit}} vastusevariandi poolt