Fluorescence-based single-molecule and fluctuation spectroscopy in the near-IR can open avenues for biomolecular dynamic studies in biological media with suppressed autofluorescence and scattering background. However, further implementation is limited by the lower brightness of NIR fluorophores and available single-photon detector technologies that are still to be explored and adapted. Superconducting nanowire single-photon detectors (snSPDs) have found increasing use in quantum optics and optical communication applications thanks to high sensitivity in the near-infraed (NIR), low dark-counts, no after-pulsing, and high time resolution. Here, we present characterization of fluorescence intensity fluctuations from single vesicles and NIR fluorophores based on fluorescence correlation spectroscopy (FCS), specifically taking advantage of these snSPD properties. We present a concept allowing multiplexed readouts based on only one snSPD, in which the emitted photons are separated by their emission wavelength into different optical paths, thereby translating the emission wavelengths into different arrival times onto the snSPD. This concept allows one-laser-one-detector, dual-color fluorescence cross-correlation spectroscopy (FCCS) measurements, with fluorescence intensity fluctuations of two fluorophore species separately analyzed and cross-correlated. It is shown how two fluorophore species in a sample can be distinguished by their different blinking kinetics, fluorescence lifetimes, and/or diffusion properties. Apart from differences in emission spectra, the presented concept for multiplexing using a single detector can also be applied to distinguish emitters by properties such as polarization, coherence lengths, and fluorescence bunching and antibunching signatures. It can also be generalized to other modalities than FCS, including single-molecule detection, confocal microscopy, and imaging.
{"title":"Multiplexed Near-IR Detection of Single-Molecule Fluorescence Fluctuations Using a Single Superconducting Nanowire Single-Photon Detector","authors":"Abhilash Kulkarni, Niusha Bagheri, Jerker Widengren","doi":"10.1021/acsphotonics.5c00224","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00224","url":null,"abstract":"Fluorescence-based single-molecule and fluctuation spectroscopy in the near-IR can open avenues for biomolecular dynamic studies in biological media with suppressed autofluorescence and scattering background. However, further implementation is limited by the lower brightness of NIR fluorophores and available single-photon detector technologies that are still to be explored and adapted. Superconducting nanowire single-photon detectors (snSPDs) have found increasing use in quantum optics and optical communication applications thanks to high sensitivity in the near-infraed (NIR), low dark-counts, no after-pulsing, and high time resolution. Here, we present characterization of fluorescence intensity fluctuations from single vesicles and NIR fluorophores based on fluorescence correlation spectroscopy (FCS), specifically taking advantage of these snSPD properties. We present a concept allowing multiplexed readouts based on only one snSPD, in which the emitted photons are separated by their emission wavelength into different optical paths, thereby translating the emission wavelengths into different arrival times onto the snSPD. This concept allows one-laser-one-detector, dual-color fluorescence cross-correlation spectroscopy (FCCS) measurements, with fluorescence intensity fluctuations of two fluorophore species separately analyzed and cross-correlated. It is shown how two fluorophore species in a sample can be distinguished by their different blinking kinetics, fluorescence lifetimes, and/or diffusion properties. Apart from differences in emission spectra, the presented concept for multiplexing using a single detector can also be applied to distinguish emitters by properties such as polarization, coherence lengths, and fluorescence bunching and antibunching signatures. It can also be generalized to other modalities than FCS, including single-molecule detection, confocal microscopy, and imaging.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"26 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723824","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}
In a moiré structure formed by isotropic semiconducting transition metal dichalcogenide (TMD), tuning the isotropic excitons to be anisotropic is quite challenging. Herein, by introducing controllable in-plane interlayer uniaxial strain to a MoS2 monolayer (ML) and stacking it to another unstrained ML MoS2, we successfully prepared an artificial bilayer (BL) moiré structure with heterostrain. The intralayer direct and indirect excitons within this structure demonstrate pronounced anisotropic photoluminescence (PL) emissions at both ambient and low temperatures. At 80 K, the PL anisotropic ratios of indirect and direct excitons can be enhanced to 1.45 and 1.31, respectively, in samples subjected to tensile heterostrain. These findings significantly advance our understanding of the anisotropic optical behaviors exhibited by moiré excitons of TMD materials, potentially paving the way for the design of future anisotropic twistronic devices.
{"title":"Anisotropic Excitonic Photoluminescence Observed on Artificial Bilayer MoS2 with Heterostrain","authors":"Xiaoan Jiang, Xiaoxu Zhao, Weitao Su, Fei Chen, Senjiang Yu, Yijie Zeng, Hong-Wei Lu, Peiqing Chen","doi":"10.1021/acsphotonics.4c02539","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02539","url":null,"abstract":"In a moiré structure formed by isotropic semiconducting transition metal dichalcogenide (TMD), tuning the isotropic excitons to be anisotropic is quite challenging. Herein, by introducing controllable in-plane interlayer uniaxial strain to a MoS<sub>2</sub> monolayer (ML) and stacking it to another unstrained ML MoS<sub>2</sub>, we successfully prepared an artificial bilayer (BL) moiré structure with heterostrain. The intralayer direct and indirect excitons within this structure demonstrate pronounced anisotropic photoluminescence (PL) emissions at both ambient and low temperatures. At 80 K, the PL anisotropic ratios of indirect and direct excitons can be enhanced to 1.45 and 1.31, respectively, in samples subjected to tensile heterostrain. These findings significantly advance our understanding of the anisotropic optical behaviors exhibited by moiré excitons of TMD materials, potentially paving the way for the design of future anisotropic twistronic devices.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"183 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713445","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}
Pub Date : 2025-03-27DOI: 10.1021/acsphotonics.4c02024
Laura Martinez Maestro, Miguel A. Antón, Eduardo Cabrera-Granado, Rosa Weigand, Javier Hernandez-Rueda
Today, upconverting luminescent particles are routinely used as accurate and reliable probes to remotely measure the temperature of minute volumes of matter on the order of attoliters. Lanthanide-doped particles exhibit adaptability as optical nanothermometers within biological systems, aiding the understanding of cellular dynamics, pathology, and physiology. Herein, we investigate the intrinsic optical response of Er/Yb-doped single particles levitating in a vacuum and compare it with the collective response of ensembles of particles embedded in application-relevant wet and dry environments. We make use of a quadrupole Paul trap that employs a time-varying electric field to confine single Er/Yb-doped particles in a vacuum and a thermal bath module to study particles in the above-mentioned environments. Both subsystems use twin-excitation/detection setups that allow us to record luminescence spectra, covering 4 orders of magnitude in laser intensity (e.g., 10–1–103 W/cm2 at 980 nm) and temperatures from 20 up to 200 °C. We revisit the well-established reliability of ratiometric measurements to accurately measure temperature. We find an almost perfect overlap of the experimental Boltzmann factor as a function of temperature for water, ethanol, and air–substrate environments, which is then used to retrieve the temperature of particles levitating in vacuum. We also explored the influence of the surrounding environment for increasing laser intensities by numerically and experimentally examining the balance among relevant emission bands. Our simulations qualitatively reproduce the experimentally measured luminescence in different environments, yielding a single model to simultaneously explain the laser intensity dependence of UV–NIR transitions for both the low and strong laser excitation regimes. Our findings hold great potential to expand the range of applicability of upconverting particles as dual sensors of temperature and laser intensity in different media relevant to biological and nanophotonic applications.
{"title":"Intrinsic Optical Response of Levitating Upconverting Single Particles","authors":"Laura Martinez Maestro, Miguel A. Antón, Eduardo Cabrera-Granado, Rosa Weigand, Javier Hernandez-Rueda","doi":"10.1021/acsphotonics.4c02024","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02024","url":null,"abstract":"Today, upconverting luminescent particles are routinely used as accurate and reliable probes to remotely measure the temperature of minute volumes of matter on the order of attoliters. Lanthanide-doped particles exhibit adaptability as optical nanothermometers within biological systems, aiding the understanding of cellular dynamics, pathology, and physiology. Herein, we investigate the intrinsic optical response of Er/Yb-doped single particles levitating in a vacuum and compare it with the collective response of ensembles of particles embedded in application-relevant wet and dry environments. We make use of a quadrupole Paul trap that employs a time-varying electric field to confine single Er/Yb-doped particles in a vacuum and a thermal bath module to study particles in the above-mentioned environments. Both subsystems use twin-excitation/detection setups that allow us to record luminescence spectra, covering 4 orders of magnitude in laser intensity (e.g., 10<sup>–1</sup>–10<sup>3</sup> W/cm<sup>2</sup> at 980 nm) and temperatures from 20 up to 200 °C. We revisit the well-established reliability of ratiometric measurements to accurately measure temperature. We find an almost perfect overlap of the experimental Boltzmann factor as a function of temperature for water, ethanol, and air–substrate environments, which is then used to retrieve the temperature of particles levitating in vacuum. We also explored the influence of the surrounding environment for increasing laser intensities by numerically and experimentally examining the balance among relevant emission bands. Our simulations qualitatively reproduce the experimentally measured luminescence in different environments, yielding a single model to simultaneously explain the laser intensity dependence of UV–NIR transitions for both the low and strong laser excitation regimes. Our findings hold great potential to expand the range of applicability of upconverting particles as dual sensors of temperature and laser intensity in different media relevant to biological and nanophotonic applications.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"72 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713444","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}
Pub Date : 2025-03-27DOI: 10.1021/acsphotonics.5c00036
Chao Han, Jiayue Han, Lei Guo, Xingwei Han, Meiyu He, Yurong Zhang, Zhiming Wu, He Yu, Jun Gou, Jun Wang
The development of multifunctional photodetectors that integrate sensing, storage, and computing to mimic the human visual system for efficient image processing is a key area of research. In particular, retina-inspired optoelectronic devices with multispectral information preprocessing capabilities are critical for constructing neuromorphic visual systems; however, achieving this in traditional photodetectors is challenging due to the lack of suitable photoresponse modes. Herein, a graphene/organic photodetector (GOP) with a spectral-tunable photoresponse memory mode switching feature is demonstrated. Benefiting from the unique photogenerated charge transfer and trapping behavior in the heterojunction, the device exhibits memory-free (with recovery times of a few milliseconds) and long-memory (with recovery times of several hundred seconds) photoresponse modes under long-wavelength (650–1064 nm) and short-wavelength (370–520 nm) light stimulation, respectively. Furthermore, the device supports spectral-tunable dual-mode switching between photosynaptic and photodetection under multiple light pulse stimulations, enabling real-time preprocessing of images with mixed green and red dual-wavelength information using a GOP-based 3 × 3-pixel image sensor. We also demonstrate a GOP-constructed neuromorphic visual system for efficient image processing, where the front-end GOP-based image sensor filters out background noise in the input images, significantly improving the image recognition accuracy of the back-end GOP-connected artificial neural network (from 40 to 93%).
{"title":"Retina-Inspired Dual-Mode Photodetector with Spectral-Tunable Memory Switching for Neuromorphic Visual Systems","authors":"Chao Han, Jiayue Han, Lei Guo, Xingwei Han, Meiyu He, Yurong Zhang, Zhiming Wu, He Yu, Jun Gou, Jun Wang","doi":"10.1021/acsphotonics.5c00036","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00036","url":null,"abstract":"The development of multifunctional photodetectors that integrate sensing, storage, and computing to mimic the human visual system for efficient image processing is a key area of research. In particular, retina-inspired optoelectronic devices with multispectral information preprocessing capabilities are critical for constructing neuromorphic visual systems; however, achieving this in traditional photodetectors is challenging due to the lack of suitable photoresponse modes. Herein, a graphene/organic photodetector (GOP) with a spectral-tunable photoresponse memory mode switching feature is demonstrated. Benefiting from the unique photogenerated charge transfer and trapping behavior in the heterojunction, the device exhibits memory-free (with recovery times of a few milliseconds) and long-memory (with recovery times of several hundred seconds) photoresponse modes under long-wavelength (650–1064 nm) and short-wavelength (370–520 nm) light stimulation, respectively. Furthermore, the device supports spectral-tunable dual-mode switching between photosynaptic and photodetection under multiple light pulse stimulations, enabling real-time preprocessing of images with mixed green and red dual-wavelength information using a GOP-based 3 × 3-pixel image sensor. We also demonstrate a GOP-constructed neuromorphic visual system for efficient image processing, where the front-end GOP-based image sensor filters out background noise in the input images, significantly improving the image recognition accuracy of the back-end GOP-connected artificial neural network (from 40 to 93%).","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"1 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713446","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}
In recent years, advancements in optical scattering of nanostructures have significantly driven the development of telecommunications, medical imaging, detection, and novel light sources. However, due to the structural complexity of nanostructures, particularly metasurfaces and metamaterials, traditional methods of full-wave modeling for simulating optical scattering face substantial challenges due to increased degrees of freedom. In this work, we propose a symmetry-adapted finite element method to reduce the computational domain and enhance the efficiency of optical scattering simulations. By introducing the concepts of symmetry group and projection operator, we offer a formal and rigorous framework for decomposing the original problem, i.e., the incident condition, boundary constraints, and the finite element method implementation in decoupled subtasks. To demonstrate its broad applicability, we present three numerical examples: the enhancement of light confinement via quasi-bound states in the continuum in a photonic crystal slab, the scattering cross sections of incident configurations, and the calculation of transmission spectra in the metasurface. These examples illustrate the use of the symmetry finite element method under different symmetry conditions, including mirror symmetry, rotational symmetry, and the combination of Bloch’s theorem. Our method significantly reduces computation time and memory usage, thereby greatly improving the computational efficiency. Given the universality of symmetry principles, our method has important applications in the optical analysis and design of symmetric photonic devices, especially for symmetric yet large-sized optical structures.
{"title":"Efficient Finite Element Modeling of Light Scattering in Symmetric Structures: A Nondegenerate Case","authors":"Jingwei Wang, Lida Liu, Yuhao Jing, Zhongfei Xiong, Dominik Kowal, Yuntian Chen","doi":"10.1021/acsphotonics.4c02474","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02474","url":null,"abstract":"In recent years, advancements in optical scattering of nanostructures have significantly driven the development of telecommunications, medical imaging, detection, and novel light sources. However, due to the structural complexity of nanostructures, particularly metasurfaces and metamaterials, traditional methods of full-wave modeling for simulating optical scattering face substantial challenges due to increased degrees of freedom. In this work, we propose a symmetry-adapted finite element method to reduce the computational domain and enhance the efficiency of optical scattering simulations. By introducing the concepts of symmetry group and projection operator, we offer a formal and rigorous framework for decomposing the original problem, i.e., the incident condition, boundary constraints, and the finite element method implementation in decoupled subtasks. To demonstrate its broad applicability, we present three numerical examples: the enhancement of light confinement via quasi-bound states in the continuum in a photonic crystal slab, the scattering cross sections of incident configurations, and the calculation of transmission spectra in the metasurface. These examples illustrate the use of the symmetry finite element method under different symmetry conditions, including mirror symmetry, rotational symmetry, and the combination of Bloch’s theorem. Our method significantly reduces computation time and memory usage, thereby greatly improving the computational efficiency. Given the universality of symmetry principles, our method has important applications in the optical analysis and design of symmetric photonic devices, especially for symmetric yet large-sized optical structures.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"57 14 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713807","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}
Pub Date : 2025-03-25DOI: 10.1021/acsphotonics.5c00137
Zhe Shen, Ning Liu
Optical tweezers with structured light expand the degrees of freedom of particle manipulation. However, studies of structured optical tweezers are usually accompanied by complex theoretical models, strict simulation conditions, and uncertain experimental factors, which may bring about high time costs and insufficiently precise results. In this work, we proposed a bidirectional neural network model for the analysis and design of optical tweezers with optical vortices, as a typical structured light beam. The deep learning network derived from the convolutional neural network was optimized to fit the optical vortex tweezers model. In analyzing optical forces, the network can achieve over 98% accuracy and improve computational efficiency by more than 20 times. In further analyzing particle trajectories, the network can also achieve over 95.5% accuracy. Meanwhile, in optical tweezers with vortex-like beams, our network can still predict particle motion behavior with a high accuracy of up to 96.2%. Our network can inversely design optical vortex tweezers on demand with 95.4% accuracy. In addition, the experimental results in optical tweezers with a plasmonic vortex can be analyzed by the proposed model, which can be used to achieve arbitrary optical manipulation. Our work demonstrates that the proposed deep learning network can provide an effective algorithmic platform for the analysis and design of optical tweezers and is expected to promote the application of optical tweezers in biomedicine.
{"title":"Optical Tweezers with Optical Vortex Based on Deep Learning","authors":"Zhe Shen, Ning Liu","doi":"10.1021/acsphotonics.5c00137","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00137","url":null,"abstract":"Optical tweezers with structured light expand the degrees of freedom of particle manipulation. However, studies of structured optical tweezers are usually accompanied by complex theoretical models, strict simulation conditions, and uncertain experimental factors, which may bring about high time costs and insufficiently precise results. In this work, we proposed a bidirectional neural network model for the analysis and design of optical tweezers with optical vortices, as a typical structured light beam. The deep learning network derived from the convolutional neural network was optimized to fit the optical vortex tweezers model. In analyzing optical forces, the network can achieve over 98% accuracy and improve computational efficiency by more than 20 times. In further analyzing particle trajectories, the network can also achieve over 95.5% accuracy. Meanwhile, in optical tweezers with vortex-like beams, our network can still predict particle motion behavior with a high accuracy of up to 96.2%. Our network can inversely design optical vortex tweezers on demand with 95.4% accuracy. In addition, the experimental results in optical tweezers with a plasmonic vortex can be analyzed by the proposed model, which can be used to achieve arbitrary optical manipulation. Our work demonstrates that the proposed deep learning network can provide an effective algorithmic platform for the analysis and design of optical tweezers and is expected to promote the application of optical tweezers in biomedicine.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"96 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695082","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}
Exciton-polaritons are composite bosonic quasiparticles formed by the strong coupling of photons and excitons, possessing a hybrid light-matter nature. Under certain conditions, they can achieve Bose–Einstein condensation at room temperature. Additionally, the information carried by photons leaking during their recombination process can be detected in real space. In this paper, halide perovskite materials are utilized within an optical microcavity to design a microdisk with a radius of 3 μm for confining exciton-polaritons. This approach achieves room-temperature condensation of exciton-polaritons in a perovskite crystal potential well and allows for the control of modes with symmetric petal-like shapes. We experimentally and theoretically demonstrate that controlling the relative position of the pump beam and the microdisk enables simultaneous switching of the angular and radial modes of exciton-polaritons, which manifest in real space as petal modes with different numbers of petals and layers. We have achieved the switching between the following modes: low-order petal modes with angular quantum numbers l = 1 and l = 2, characterized by single-orbit petal structures, and high-order petal modes with an angular quantum number l = 7, characterized by multiradial-node petal structures. Polaritons in these modes condense at multiple energy levels of the two lower branches. This study has important implications for the research and development of room-temperature exciton-polariton-based optical logic devices.
激子-极化子是光子和激子强耦合形成的复合玻色子准粒子，具有光-物质混合性质。在一定条件下，它们可以在室温下实现玻色-爱因斯坦凝聚。此外，它们在重组过程中泄露的光子所携带的信息可以在现实空间中被探测到。本文在光学微腔内利用卤化物包晶材料设计了一个半径为 3 μm 的微盘，用于约束激子-极坐标子。这种方法实现了激子-极化子在过氧化物晶体势阱中的室温凝聚，并可控制具有对称花瓣状形状的模式。我们通过实验和理论证明，控制泵浦光束和微盘的相对位置可以同时切换激子-极化子的角度和径向模式，这些模式在现实空间中表现为具有不同花瓣数和层数的花瓣模式。我们实现了以下模式之间的切换：角量子数为 l = 1 和 l = 2 的低阶花瓣模式，其特征是单轨道花瓣结构；角量子数为 l = 7 的高阶花瓣模式，其特征是多轴节点花瓣结构。这些模式中的极化子在两个低分支的多个能级上凝聚。这项研究对研究和开发基于室温激子-极化子的光学逻辑器件具有重要意义。
{"title":"Maneuverable Optical Selection of Multi-Branch Exciton-Polariton Modes in Disk-Shaped Perovskite Microcavities","authors":"Yifan Dong, Hao Wu, Xiaokun Zhai, Baili Li, Qixian Xie, Zhenyu Xiong, Peicheng Liu, Yanmei Li, Yuan Ren","doi":"10.1021/acsphotonics.4c02319","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02319","url":null,"abstract":"Exciton-polaritons are composite bosonic quasiparticles formed by the strong coupling of photons and excitons, possessing a hybrid light-matter nature. Under certain conditions, they can achieve Bose–Einstein condensation at room temperature. Additionally, the information carried by photons leaking during their recombination process can be detected in real space. In this paper, halide perovskite materials are utilized within an optical microcavity to design a microdisk with a radius of 3 μm for confining exciton-polaritons. This approach achieves room-temperature condensation of exciton-polaritons in a perovskite crystal potential well and allows for the control of modes with symmetric petal-like shapes. We experimentally and theoretically demonstrate that controlling the relative position of the pump beam and the microdisk enables simultaneous switching of the angular and radial modes of exciton-polaritons, which manifest in real space as petal modes with different numbers of petals and layers. We have achieved the switching between the following modes: low-order petal modes with angular quantum numbers <i>l</i> = 1 and <i>l</i> = 2, characterized by single-orbit petal structures, and high-order petal modes with an angular quantum number <i>l</i> = 7, characterized by multiradial-node petal structures. Polaritons in these modes condense at multiple energy levels of the two lower branches. This study has important implications for the research and development of room-temperature exciton-polariton-based optical logic devices.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"17 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703507","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}
Strong light-matter coupling has garnered significant attention for its potential to optimize optoelectronic responses. In this study, we designed open cavities featuring nonlocal metasurfaces composed of aluminum nanoparticle arrays. The surface lattice resonances in these metasurfaces exhibit electronic strong coupling with the boron difluoride curcuminoid derivative, which is known for its highly efficient thermally activated delayed fluorescence in the near-infrared. Our results show that delayed fluorescence induced by triplet–triplet annihilation can be enhanced by a factor of 2.0–2.6 in metasurfaces that are either tuned or detuned to the molecular electronic transition. We demonstrate that delayed fluorescence enhancements in these systems primarily stem from increased absorption in the organic layer caused by the nanoparticle array, while strong coupling has negligible effects on reverse intersystem crossing rates, aligning with previous studies. We support these findings with finite-difference-time-domain simulations. This study elucidates how light-matter interactions affect delayed fluorescence, highlighting the potential applications in optoelectronic devices.
{"title":"Enhanced Delayed Fluorescence in Nonlocal Metasurfaces: The Role of Electronic Strong Coupling","authors":"Yu-Chen Wei, Chih-Hsing Wang, Konstantinos S. Daskalakis, Pi-Tai Chou, Shunsuke Murai, Jaime Gómez Rivas","doi":"10.1021/acsphotonics.5c00124","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00124","url":null,"abstract":"Strong light-matter coupling has garnered significant attention for its potential to optimize optoelectronic responses. In this study, we designed open cavities featuring nonlocal metasurfaces composed of aluminum nanoparticle arrays. The surface lattice resonances in these metasurfaces exhibit electronic strong coupling with the boron difluoride curcuminoid derivative, which is known for its highly efficient thermally activated delayed fluorescence in the near-infrared. Our results show that delayed fluorescence induced by triplet–triplet annihilation can be enhanced by a factor of 2.0–2.6 in metasurfaces that are either tuned or detuned to the molecular electronic transition. We demonstrate that delayed fluorescence enhancements in these systems primarily stem from increased absorption in the organic layer caused by the nanoparticle array, while strong coupling has negligible effects on reverse intersystem crossing rates, aligning with previous studies. We support these findings with finite-difference-time-domain simulations. This study elucidates how light-matter interactions affect delayed fluorescence, highlighting the potential applications in optoelectronic devices.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"33 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703506","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}
It is challenging to quantify the self-healing efficiency in crystalline materials with atomic precision. Organic crystals with self-healing capabilities are of particular interest due to their wide-ranging potential applications. In this study, we present a comprehensive polarization Mueller matrix analysis of a self-healing crystal. Our results not only probe and quantify the crystal’s various optical properties but also offer new insights into its self-healing mechanism. We observe that the mechanical stress-induced changes of the microscopic polarization properties of the crystal are manifested as the reduction of anisotropic parameters, e.g., diattenuation and retardance, in the imperfectly healed and fractured crystal. This reduction in amplitude and phase anisotropy parameters is interpreted as the manifestation of the photoelastic effect, where some remnant strain within the broken crystal leads to the alteration of the dielectric tensor of the anisotropic crystal. These alterations, in turn, explain changes in the macroscopic piezoelectric polarization through the orientation of the permanent dipoles and the generation of stress-induced surface charges, which leads to the autonomous self-healing of the crystal. Beyond its remarkable self-healing properties, the crystal also exhibits rich optical properties, e.g., strong polarization anisotropy effects, nonlinear properties, etc.
{"title":"Self-Healing Behavior of Piezoelectric Crystals Studied Using Polarized Light","authors":"Nishkarsh Kumar, Jeeban Kumar Nayak, Surojit Bhunia, Shubham Chandel, Asima Pradhan, C. Malla Reddy, Nirmalya Ghosh","doi":"10.1021/acsphotonics.4c02243","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02243","url":null,"abstract":"It is challenging to quantify the self-healing efficiency in crystalline materials with atomic precision. Organic crystals with self-healing capabilities are of particular interest due to their wide-ranging potential applications. In this study, we present a comprehensive polarization Mueller matrix analysis of a self-healing crystal. Our results not only probe and quantify the crystal’s various optical properties but also offer new insights into its self-healing mechanism. We observe that the mechanical stress-induced changes of the microscopic polarization properties of the crystal are manifested as the reduction of anisotropic parameters, e.g., diattenuation and retardance, in the imperfectly healed and fractured crystal. This reduction in amplitude and phase anisotropy parameters is interpreted as the manifestation of the photoelastic effect, where some remnant strain within the broken crystal leads to the alteration of the dielectric tensor of the anisotropic crystal. These alterations, in turn, explain changes in the macroscopic piezoelectric polarization through the orientation of the permanent dipoles and the generation of stress-induced surface charges, which leads to the autonomous self-healing of the crystal. Beyond its remarkable self-healing properties, the crystal also exhibits rich optical properties, e.g., strong polarization anisotropy effects, nonlinear properties, etc.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"34 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695081","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}
Pub Date : 2025-03-24DOI: 10.1021/acsphotonics.4c02569
Yahui Huang, Jianyu Yang, Yong Wang, Bo Dai
Although the transverse thermoelectric (TTE) effect has been proposed for infrared (IR) laser detection, the development of cost-effective TTE materials for high-energy IR detection remains challenging. This work proposes a groundbreaking TTE material based on c-axis 4° tilted n-type 4H-SiC single crystals for IR laser detector applications. Pulsed lasers with wavelengths of 1080 nm and durations ranging from 5 to 40 ms were used as the irradiation sources. The voltages recorded on the 4H-SiC surface were demonstrated to originate from the TTE effect, driven by Seebeck coefficient anisotropy, as made evident by comparing signals from various electrode pairs. Additionally, the influence of the laser incidence angle on the peak voltage and decay time was investigated, which may enhance the theoretical understanding of the TTE effect. Furthermore, the response of the detectors at elevated temperatures, from room temperature (RT) to 400 °C, was evaluated. These results suggest that 4H-SiC single crystals are promising low-cost TTE materials for high-energy IR detection.
{"title":"Exploring the Transverse Thermoelectric Effect of 4H-SiC Single Crystal for the Applications of High-Energy Infrared Laser Detection","authors":"Yahui Huang, Jianyu Yang, Yong Wang, Bo Dai","doi":"10.1021/acsphotonics.4c02569","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02569","url":null,"abstract":"Although the transverse thermoelectric (TTE) effect has been proposed for infrared (IR) laser detection, the development of cost-effective TTE materials for high-energy IR detection remains challenging. This work proposes a groundbreaking TTE material based on <i>c</i>-axis 4° tilted n-type 4H-SiC single crystals for IR laser detector applications. Pulsed lasers with wavelengths of 1080 nm and durations ranging from 5 to 40 ms were used as the irradiation sources. The voltages recorded on the 4H-SiC surface were demonstrated to originate from the TTE effect, driven by Seebeck coefficient anisotropy, as made evident by comparing signals from various electrode pairs. Additionally, the influence of the laser incidence angle on the peak voltage and decay time was investigated, which may enhance the theoretical understanding of the TTE effect. Furthermore, the response of the detectors at elevated temperatures, from room temperature (RT) to 400 °C, was evaluated. These results suggest that 4H-SiC single crystals are promising low-cost TTE materials for high-energy IR detection.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"21 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695084","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}
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