Nature PhotonicsPub Date : 2025-05-26DOI: 10.1038/s41566-025-01675-4
Luca Sortino, Jonas Biechteler, Lucas Lafeta, Lucca Kühner, Achim Hartschuh, Leonardo de S. Menezes, Stefan A. Maier, Andreas Tittl
{"title":"Atomic-layer assembly of ultrathin optical cavities in van der Waals heterostructure metasurfaces","authors":"Luca Sortino, Jonas Biechteler, Lucas Lafeta, Lucca Kühner, Achim Hartschuh, Leonardo de S. Menezes, Stefan A. Maier, Andreas Tittl","doi":"10.1038/s41566-025-01675-4","DOIUrl":"10.1038/s41566-025-01675-4","url":null,"abstract":"Photonics has been revolutionized by advances in optical metasurfaces, unlocking design and engineering opportunities for flat optical components. Similarly, layered two-dimensional materials have enabled breakthroughs in physics via the deterministic assembly of vertical heterostructures, allowing precise control over the atomic composition of each layer. However, integrating these fields into a single system has remained challenging, limiting progress in atomic-scale optical cavities and metamaterials. Here we demonstrate the concept of van der Waals heterostructure metasurfaces, where ultrathin multilayer van der Waals material stacks are shaped into precisely engineered resonant nanostructures for enhancing light–matter interactions. By leveraging quasi-bound states in the continuum physics, we create intrinsic high-quality-factor resonances originating from WS2 monolayers encapsulated in hexagonal boron nitride at thicknesses below 130 nm, achieving room-temperature strong coupling and polaritonic photoluminescence emission. Furthermore, the metasurface-coupled exciton–polaritons exhibit strong nonlinearities, leading to a saturation of the strong-coupling regime at ultralow fluences of <1 nJ cm–2, three orders of magnitude lower than in previous two-dimensional-material-based cavity systems. Our approach monolithically integrates metasurfaces and van der Waals materials and can be extended to the vast library of existing two-dimensional materials, unlocking new avenues for ambient operation of ultrathin polaritonic devices with atomic-scale precision and control. Ultrathin multilayer van der Waals material stacks are shaped into precisely engineered resonant nanostructures, giving strong nonlinearities at ultralow fluences of <1 nJ cm–2, more than three orders of magnitude smaller than in previous two-dimensional-material-based cavity systems.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 8","pages":"825-832"},"PeriodicalIF":32.9,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41566-025-01675-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144137090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-23DOI: 10.1038/s41566-025-01667-4
Qing-Xin Ji, Wei Zhang, Anatoliy Savchenkov, Peng Liu, Shuman Sun, Warren Jin, Joel Guo, Jonathan Peters, Lue Wu, Avi Feshali, Mario Paniccia, Vladimir Ilchenko, John Bowers, Andrey Matsko, Kerry Vahala
{"title":"Dispersive-wave-agile optical frequency division","authors":"Qing-Xin Ji, Wei Zhang, Anatoliy Savchenkov, Peng Liu, Shuman Sun, Warren Jin, Joel Guo, Jonathan Peters, Lue Wu, Avi Feshali, Mario Paniccia, Vladimir Ilchenko, John Bowers, Andrey Matsko, Kerry Vahala","doi":"10.1038/s41566-025-01667-4","DOIUrl":"10.1038/s41566-025-01667-4","url":null,"abstract":"The remarkable frequency stability of resonant systems in the optical domain (optical cavities and atomic transitions) can be harnessed at frequency scales accessible by electronics using optical frequency division. This capability is revolutionizing technologies spanning time keeping to high-performance electrical signal sources. A version of the technique called two-point optical frequency division (2P-OFD) is proving advantageous for application to high-performance signal sources. In 2P-OFD, an optical cavity anchors two spectral endpoints defined by lines of a frequency comb. The comb need not be self-referenced, which greatly simplifies the system architecture and reduces power requirements. Here, a 2P-OFD microwave signal source is demonstrated with record-low phase noise using a microcomb. Key to this advance is a spectral endpoint defined by a frequency-agile single-mode dispersive wave that is emitted by the microcomb soliton. Moreover, the system frequency reference is a compact all-solid-state optical cavity with a record Q factor. A hybridly packaged version of the system offers excellent longer term stability. The results advance integrable microcomb-based signal sources into the performance realm of much larger microwave sources. Using two-point optical frequency division based on a frequency-agile single-mode dispersive wave, a microwave signal source with record-low phase noise using a microcomb is demonstrated, offering over tenfold lower phase noise than state-of-the-art approaches.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 6","pages":"624-629"},"PeriodicalIF":32.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41566-025-01667-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-23DOI: 10.1038/s41566-025-01683-4
Zimo Zhang, Zhongxiao Xu, Ran Huang, Xingda Lu, Fengbo Zhang, Donghao Li, Şahin K. Özdemir, Franco Nori, Han Bao, Yanhong Xiao, Bing Chen, Hui Jing, Heng Shen
{"title":"Chirality-induced quantum non-reciprocity","authors":"Zimo Zhang, Zhongxiao Xu, Ran Huang, Xingda Lu, Fengbo Zhang, Donghao Li, Şahin K. Özdemir, Franco Nori, Han Bao, Yanhong Xiao, Bing Chen, Hui Jing, Heng Shen","doi":"10.1038/s41566-025-01683-4","DOIUrl":"10.1038/s41566-025-01683-4","url":null,"abstract":"Chirality, non-reciprocity and quantum correlations are at the centre of a wide range of intriguing effects and applications across natural sciences and emerging quantum technologies. However, the direct link combining these three essential concepts has remained unexplored. Here we establish a chiral non-Hermitian platform with flying atoms and demonstrate chirality-induced non-reciprocal bipartite quantum correlations between two channels: quantum correlation emerges when two spatially separated light beams with the same polarization propagate in opposite directions in the atomic cloud, and it becomes zero when they travel in the same direction. Thus, by just flipping the propagation direction of one of the beams and keeping its polarization the same as the other beam, we can create or annihilate quantum correlations between the two channels. We also show that this non-reciprocal quantum correlation can be extended to multicolour sidebands with Floquet engineering. Our findings may pave the road for realizing one-way quantum effects, such as non-reciprocal squeezing or entanglement, with a variety of chiral devices, for emerging applications in, for example, directional quantum networks or non-reciprocal quantum metrology. Chirality-induced quantum non-reciprocity of cross-channel correlations is demonstrated in a rubidium vapour system by flipping the flow direction of one of the circularly polarized laser beams. It can be extended to multicolour sidebands with Floquet engineering.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 8","pages":"840-846"},"PeriodicalIF":32.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-23DOI: 10.1038/s41566-025-01669-2
Xing Jin, Zhenyu Xie, Xiangpeng Zhang, Hanfei Hou, Bingyan Wu, Fangxing Zhang, Xuanyi Zhang, Lin Chang, Qihuang Gong, Qi-Fan Yang
{"title":"Microresonator-referenced soliton microcombs with zeptosecond-level timing noise","authors":"Xing Jin, Zhenyu Xie, Xiangpeng Zhang, Hanfei Hou, Bingyan Wu, Fangxing Zhang, Xuanyi Zhang, Lin Chang, Qihuang Gong, Qi-Fan Yang","doi":"10.1038/s41566-025-01669-2","DOIUrl":"10.1038/s41566-025-01669-2","url":null,"abstract":"Optical frequency division relies on optical frequency combs to translate ultrastable optical frequency references coherently to the microwave domain. This technology has enabled the synthesis of microwave signals with ultralow timing noise; however, the necessary instrumentation remains too bulky for practical applications. Recently, efforts have focused on leveraging microphotonic technologies to enhance system compactness. Here we develop an optical frequency division system using microresonator-based frequency references and comb generators. The soliton microcomb formed in an integrated Si3N4 microresonator is stabilized to two lasers referenced to an ultrahigh-quality-factor MgF2 microresonator. Photodetection of the soliton pulse train produces 25-GHz microwaves with an absolute phase noise of –141 dBc Hz–1 (546 zs Hz−1/2) at a 10-kHz offset frequency, which can be further referenced to an atomic clock for improved long-term stability. The synthesized microwave signals are evaluated as carrier waves in communication and radar applications, demonstrating enhanced fidelity and sensitivity against interference compared with those derived from electronic oscillators. Our work demonstrates unprecedented coherence in microphotonic microwave oscillators, providing key building blocks for next-generation timekeeping, navigation and satellite communication systems. A compact optical frequency division system with magnesium-fluoride-microresonator-based frequency references and silicon-nitride-microresonator-based comb generators is reported, offering a soliton pulse train at 25-GHz microwaves with an absolute phase noise of –141 dBc Hz–1 and timing noise below 546 zs Hz–1/2 at a 10-kHz offset frequency.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 6","pages":"630-636"},"PeriodicalIF":32.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-23DOI: 10.1038/s41566-025-01668-3
Shuman Sun, Mark W. Harrington, Fatemehsadat Tabatabaei, Samin Hanifi, Kaikai Liu, Jiawei Wang, Beichen Wang, Zijiao Yang, Ruxuan Liu, Jesse S. Morgan, Steven M. Bowers, Paul A. Morton, Karl D. Nelson, Andreas Beling, Daniel J. Blumenthal, Xu Yi
{"title":"Microcavity Kerr optical frequency division with integrated SiN photonics","authors":"Shuman Sun, Mark W. Harrington, Fatemehsadat Tabatabaei, Samin Hanifi, Kaikai Liu, Jiawei Wang, Beichen Wang, Zijiao Yang, Ruxuan Liu, Jesse S. Morgan, Steven M. Bowers, Paul A. Morton, Karl D. Nelson, Andreas Beling, Daniel J. Blumenthal, Xu Yi","doi":"10.1038/s41566-025-01668-3","DOIUrl":"10.1038/s41566-025-01668-3","url":null,"abstract":"Optical frequency division has revolutionized microwave and millimetre-wave generation and set spectral purity records owing to its unique capability to transfer high fractional stability from optical to electronic frequencies. Recently, rapid developments in integrated optical reference cavities and microresonator-based optical frequency combs (microcombs) have created a path to transform optical frequency division technology to the chip scale. Here we demonstrate an ultralow-phase-noise millimetre-wave oscillator by leveraging integrated photonic components and microcavity Kerr optical frequency division. The oscillator derives its stability from an integrated complementary-metal–oxide–semiconductor-compatible SiN coil cavity, and the optical frequency division is achieved spontaneously through Kerr interaction in the integrated SiN microresonator between the soliton microcombs and the injected reference lasers. Besides achieving low phase noise for integrated millimetre-wave oscillators, our demonstration greatly simplifies the implementation of integrated optical frequency division oscillators and could be useful in applications of radar, spectroscopy and astronomy. By leveraging microcavity-integrated photonics and Kerr-induced optical frequency division, an integrated photonic millimetre-wave oscillator with low phase noise is demonstrated, achieving –77 dBc Hz–1 and –121 dBc Hz–1, respectively, at 100-Hz and 10-kHz offset frequencies, corresponding to –98 dBc Hz–1 and –142 dBc Hz–1 when scaled to a 10-GHz carrier.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 6","pages":"637-642"},"PeriodicalIF":32.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-23DOI: 10.1038/s41566-025-01679-0
Haonan Zhao, Claire E. Arneson, Stephen R. Forrest
{"title":"Stable, deep blue tandem phosphorescent organic light-emitting diode enabled by the double-sided polariton-enhanced Purcell effect","authors":"Haonan Zhao, Claire E. Arneson, Stephen R. Forrest","doi":"10.1038/s41566-025-01679-0","DOIUrl":"10.1038/s41566-025-01679-0","url":null,"abstract":"Blue phosphorescent organic light-emitting diodes (PHOLEDs) are highly efficient, although their short operational lifetimes have limited their commercial acceptance in displays and lighting. A high density of energetic triplet excitons accumulates in the emission layer that eventually annihilate, leading to molecular degradation. Here we report long operational lifetime, efficient and deep blue tandem PHOLEDs using the polariton-enhanced Purcell (PEP) effect at both the diode cathode and anode. The Pt- and Ir-complex-based bottom-emitting tandem PEP-PHOLEDs show a tenfold increase in lifetime and colour saturation compared with their analogous single-junction PHOLEDs. Particularly, the Pt-complex-based tandem PEP-PHOLED on flat glass substrates has lifetimes of LT90 = 830 ± 30 h and 1,800 ± 100 h (LT90 = the time to reach 90% of the initial luminance of 500 cd m−2), and forward-viewing external quantum efficiencies of 36.8 ± 0.5% or 56.0 ± 1.0% without or with substrate light extraction, respectively. The lifetime enhancement is equivalent to 250 times that of conventional single-junction Ir-based PHOLED lifetimes with similar blue chromaticity coordinates. The tandem PEP-PHOLED has chromaticity coordinates of CIExy = (0.14, 0.12) and a marginally perceptible colour shift with viewing angle up to ±75°. The double-sided PEP effect is readily integrated with other established lifetime-extending technologies, allowing for a multiplicative increase in lifetime. To our knowledge, this is the first demonstration of a deep blue PHOLED that shows stability comparable to green PHOLEDs, accelerating the use of the deep blue phosphorescent emitters in power-efficient displays and lighting. Exploiting the polariton-enhanced Purcell effect in tandem organic light-emitting diodes enables deep-blue-emitting devices with an external quantum efficiency of 36.8% and an LT90 lifetime of 830 h at an initial luminance of 500 cd m−2. These metrics are increased to 56% and 1,800 h with substrate light outcoupling.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 6","pages":"607-614"},"PeriodicalIF":32.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-21DOI: 10.1038/s41566-025-01684-3
Simon C. Boehme, Tan P. T. Nguyen, Chenglian Zhu, Ihor Cherniukh, Leon G. Feld, Dmitry N. Dirin, Maryna I. Bodnarchuk, Claudine Katan, Jacky Even, Maksym V. Kovalenko, Gabriele Rainò
{"title":"Single-photon superabsorption in CsPbBr3 perovskite quantum dots","authors":"Simon C. Boehme, Tan P. T. Nguyen, Chenglian Zhu, Ihor Cherniukh, Leon G. Feld, Dmitry N. Dirin, Maryna I. Bodnarchuk, Claudine Katan, Jacky Even, Maksym V. Kovalenko, Gabriele Rainò","doi":"10.1038/s41566-025-01684-3","DOIUrl":"10.1038/s41566-025-01684-3","url":null,"abstract":"The absorption of light via interband optical transitions plays a key role in nature and applied technology, enabling efficient photosynthesis and photovoltaic cells, fast photodetectors or sensitive (quantum) light–matter interfaces. In many such photonic systems, enhancing the light absorption strength would be beneficial for yielding higher device efficiency and enhanced speed or sensitivity. So far, however, cavity-free light absorbers feature poorly engineerable absorption rates, consistent with the notion that the coupling strength between the initial and final states is an intrinsic material parameter. By contrast, greatly enhanced absorption rates had been theoretically predicted for superradiant systems, which feature giant oscillator strength through spatially extended coherent oscillations of the electron polarization. Unlike for emission processes, however, experimental realizations of superradiance in absorption—‘superabsorption’—remain sparse and require complicated excited-state engineering approaches. Here we report superabsorption by the time reversal of single-photon superradiance in large CsPbBr3 perovskite quantum dots. Optical spectroscopy reveals a bandgap absorption that strongly increases with the quantum dot volume, consistent with a giant exciton wavefunction. Configuration-interaction calculations, quantitatively agreeing with the experiment, attribute the observed single-photon superabsorption to strong electron–hole pair-state correlations. The approach brings new opportunities for the development of more efficient optoelectronic devices and quantum light–matter interfaces. Greatly enhanced light absorption is reported in large perovskite quantum dots by realizing a transition with a giant oscillator strength at the optical bandgap.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 8","pages":"864-870"},"PeriodicalIF":32.9,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41566-025-01684-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-20DOI: 10.1038/s41566-025-01680-7
Mingming Nie, Jonathan Musgrave, Shu-Wei Huang
{"title":"Cross-polarized stimulated Brillouin scattering-empowered photonics","authors":"Mingming Nie, Jonathan Musgrave, Shu-Wei Huang","doi":"10.1038/s41566-025-01680-7","DOIUrl":"10.1038/s41566-025-01680-7","url":null,"abstract":"This paper studies cross-polarized stimulated Brillouin scattering (XP-SBS) and its integration with quadratic nonlinearity in lithium niobate to enhance photonic device performance. Three novel applications are demonstrated: (1) a reconfigurable stimulated Brillouin laser with a 0.7-Hz narrow linewidth and 40-nm tunability, enabled by the thermo-optic phase matching of XP-SBS; (2) an efficient coherent mode converter achieving 55% conversion efficiency via intracavity Brillouin-enhanced four-wave mixing; (3) a Brillouin-quadratic laser and frequency comb operational in near-infrared and visible bands, benefiting from the interaction between XP-SBS and quadratic nonlinearity. These advancements promise substantial improvements in photonic technologies, including narrow-linewidth lasers, microcomb generation and optical signal processing, paving the way for more robust and versatile applications. Cross-polarized stimulated Brillouin scattering and its integration with quadratic nonlinearity is studied in lithium niobate, which enhanced photonic device performance in a reconfigurable stimulated Brillouin laser with 0.7-Hz narrow linewidth and 40-nm tunability, an efficient coherent mode converter, and Brillouin-quadratic laser and frequency comb operational in near-infrared and visible bands.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 6","pages":"585-592"},"PeriodicalIF":32.9,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144097313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Parallel photon avalanche nanoparticles for tunable emission and multicolour sub-diffraction microscopy","authors":"Hao Dong, Lin-Quan Guan, Shuqian Qiao, Yusen Liang, Zhimin Zhu, Jin-Wen Zhang, Xiao-Yong Wang, Yue Ni, Xin Guo, Ze-Yu Lyu, Xiang-Fei Yang, Ling-Dong Sun, Qiuqiang Zhan, Chun-Hua Yan","doi":"10.1038/s41566-025-01671-8","DOIUrl":"10.1038/s41566-025-01671-8","url":null,"abstract":"Photon avalanche (PA) can generate upconversion luminescent emission that grows steeply as a function of excitation power, effectively exhibiting a high order of nonlinearity (N) that is attractive for applications ranging from photophysics studies to biophotonics. Besides the limitations in available material systems, PA is typically sustained by a single reservoir level, limiting the ability to modulate the chromaticity of the emission as well as leading to small values of N and large excitation thresholds. Here we report a parallel PA mechanism in holmium (Ho3+)-doped nanoparticles for tunable emission at room temperature. The intermediate 5I7 and 5I6 levels of Ho3+ serve as dual reservoir levels that create two parallel energy loops. This activates multiple emissive levels and enables red, green and blue PA emission under 965 nm continuous-wave excitation. By rationally engineering transition kinetics through controlling doping concentration and core/shell configuration, we demonstrate multicolour PA with large N values of 17–22 and mild excitation threshold of ~22 kW cm−2. Moreover, emission can be tailored from almost pure red to intense red, green and blue by modifying the host lattice and introducing additional cross-relaxation pathways by doping with Ce3+/Tm3+. When using the nanoparticles to label biological cells, we demonstrate multicolour imaging on a single-continuous-wave-beam microscope with lateral spatial resolution of 78 nm and 102 nm in the green–blue and red channel, respectively. These findings open the way for manufacturing nonlinear multicolour fluorophores for versatile optical and biological applications. Holmium doping endows upconversion nanoparticles with a dual-reservoir-level mechanism for parallel photon avalanche emission, enabling tunable chromaticity at room temperature, nonlinearity index up to 22 and spatial resolution for multicolour biological imaging down to 78 nm.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 7","pages":"692-700"},"PeriodicalIF":32.9,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nature PhotonicsPub Date : 2025-05-16DOI: 10.1038/s41566-025-01670-9
Lin Nan, Andrea Mancini, Thomas Weber, Geok Leng Seah, Emiliano Cortés, Andreas Tittl, Stefan A. Maier
{"title":"Angular dispersion suppression in deeply subwavelength phonon polariton bound states in the continuum metasurfaces","authors":"Lin Nan, Andrea Mancini, Thomas Weber, Geok Leng Seah, Emiliano Cortés, Andreas Tittl, Stefan A. Maier","doi":"10.1038/s41566-025-01670-9","DOIUrl":"10.1038/s41566-025-01670-9","url":null,"abstract":"Quasi-bound states in the continuum (qBICs) achieved through symmetry breaking in photonic metasurfaces are a powerful approach for engineering resonances with high quality factors and tunability. However, miniaturization of these devices is limited as the in-plane unit-cell size typically scales linearly with the resonant wavelength. By contrast, polariton resonators can be deeply subwavelength, offering a promising solution for achieving compact devices. Here we demonstrate that low-loss mid-infrared surface phonon polaritons enable metasurfaces supporting qBICs with unit-cell volumes up to 105 times smaller than the free-space volume $$lambda_{0}^3$$ . Using 100-nm-thick free-standing silicon carbide membranes, we achieve highly confined qBIC states with exceptional robustness against incident-angle variations, a feature unique among qBIC systems. This absence of angular dispersion enables mid-infrared vibrational sensing of thin, weakly absorbing molecular layers using a reflective objective, a method that typically degrades resonance quality in standard qBIC metasurfaces. We introduce surface-phonon-polariton-based qBICs as a platform for ultraconfined nanophotonic systems, advancing the miniaturization of mid-infrared sensors and devices for thermal radiation engineering. Phonon polariton quasi-bound states in the continuum realized in a dielectric metasurface patterned with a subwavelength lattice of elliptical holes in a commercially available free-standing, large-area 100-nm-thick silicon carbide membrane is demonstrated, attractive for applications in mid-infrared optics, such as molecular sensing and thermal radiation engineering.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"19 6","pages":"615-623"},"PeriodicalIF":32.9,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41566-025-01670-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}