ACS Photonics最新文献

{"title":"Inverse-Design-Assisted On-Chip GRIN Meta-Lens for Dual-Polarization Multimode Waveguide Crossing","authors":"Yingjie Liu, Xin Qiao, Xingqi Wang, Rui Wu, Zhigang Zang","doi":"10.1021/acsphotonics.4c02391","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02391","url":null,"abstract":"On-chip meta-lenses provide a flexible approach to manipulate guided waves on a chip using gradient-index subwavelength slot arrays. These arrays have recently gained attention for their compactness and reliability in functional photonic components. However, the reported schemes have only been demonstrated for single polarization. Here, the gradient-index meta-lens is utilized to realize a universal multimode waveguide crossing, which is an important component in the mode division multiplexing circuit, allowing complex network routing. For a proof-of-concept demonstration, a compact and three-channel silicon waveguide crossing for supporting six modes (three TE-polarization modes and three TM-polarization modes) is proposed and experimentally demonstrated, which has less insertion losses (<0.7 dB) and low crosstalks (<−14 dB) in the wavelength range from 1500 to 1600 nm. Moreover, a five-channel dual-mode waveguide crossing is also demonstrated, revealing that our solution can theoretically be flexibly extended to support more modes and more transmission channels. Our study paves the way for realizing dense-integration and large-capacity on-chip multimode routing and multiplexing systems.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"33 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695083","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":"Enhanced Performance of Single-Photon Emitter Hosted in Hexagonal Boron Nitride via Two-Photon Excitation","authors":"Qian Xu, Bo Gao, Liang Zhao, Gang Lv, Jianqun Yang, Xingji Li","doi":"10.1021/acsphotonics.5c00105","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00105","url":null,"abstract":"In the rapidly advancing field of quantum photonics, precise control of single-photon emitters (SPEs) is essential for the development of quantum technologies such as quantum computing, quantum communication, and quantum sensing. While single-photon excitation is widely used for SPEs, research on two-photon excitation is still limited, and its excitation mechanism remains unclear. In this study, we propose a mechanism for two-photon excitation involving two-photon absorption, excited-state reabsorption, radiative transitions, and nonradiative decay processes and also explore the low-temperature photophysical properties of the SPE hosted in hexagonal boron nitride under both single-photon and two-photon excitation conditions. Our findings demonstrate that under two-photon excitation, the SPE exhibits increased emission efficiency and decreased nonradiative losses, specifically manifested in narrower photoluminescence (PL) spectral line width, extended PL lifetime, and more robust PL emission, addressing key performance challenges of SPEs. Additionally, we provide insights into the underlying mechanisms that drive these improvements, offering a deeper understanding of how two-photon excitation enhances the photophysical properties of the SPE. This study highlights the potential of two-photon excitation to enhance the performance of the SPE and provides valuable insights for future quantum technology applications.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"71 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695087","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":"WSe2/β-Ga2O3 p–n Heterojunction-Based Normally Off Phototransistors for Self-Powered UV-C Detection","authors":"Soobeen Lee, Jeongmin Kim, Woong Choi, Jihyun Kim","doi":"10.1021/acsphotonics.4c02595","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02595","url":null,"abstract":"A WSe₂/β-Ga₂O₃ heterojunction (HJ)-based enhancement-mode (E-mode) phototransistor with self-powered operation was developed for ultraviolet-C (UV-C) photodetector applications, featuring a top-gate p-type WSe₂ (p-WSe₂) and an n-type ultrawide-bandgap β-Ga₂O₃ that serves as both the conductive channel and UV-C absorption layer. To increase the hole concentration in WSe₂ dry-transferred onto β-Ga₂O₃, the top few layers of WSe₂ were oxidized to tungsten oxide (WO_<i>x</i>) (2 &lt; <i>x</i> &lt; 3) with a high work-function value via UV–ozone treatment. High-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy revealed excellent interface quality with atomic-scale layer uniformity in the HJ of WO_<i>x</i>/WSe₂/β-Ga₂O₃. The WSe₂/β-Ga₂O₃ p–n HJ diode exhibited a high rectification ratio (∼10⁹) and an extremely low reverse current (14 fA), allowing the demonstration of a normally off n-channel β-Ga₂O₃ phototransistor integrated with an ultrathin p-WSe₂ stack. The type-II band alignment of this HJ promoted efficient separation of photogenerated electron–hole pairs under UV-C illumination, allowing us to achieve excellent optoelectronic performance under standalone operation. Without an external power source, the WSe₂/β-Ga₂O₃ E-mode phototransistor exhibited excellent optoelectronic performance, including responsivity of 2.1 A W^–1, a photo-to-dark current ratio of 1.5 × 10³, external quantum efficiency of 10.2%, specific detectivity of 6.4 × 10⁷ Jones, UV-A selectivity with a rejection ratio (<i>R</i>_254nm/<i>R</i>_365nm) of 4, and a fast response without persistent photoconductivity. These findings highlight the potential of p-WSe₂/β-Ga₂O₃ heterostructure UV-C phototransistors with high sensitivity and energy efficiency because of their compact and standalone deep-UV optoelectronic architecture.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"167 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695085","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":"Unified Simulation Platform for Optical Tweezers and Optofluidic Force Induction","authors":"Ulrich Hohenester, Marko Šimić, Raphael Hauer, Lorenz Huber, Christian Hill","doi":"10.1021/acsphotonics.5c00254","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00254","url":null,"abstract":"Optical tweezers utilize the forces exerted by focused laser beams to trap particles. In optofluidic force induction (OF2i), the forces exerted by a weakly focused laser beam trap particles in the transverse directions and push them in the laser propagation direction, which can be utilized for optical nanoparticle characterization with single-particle sensitivity. Here, we present a unified approach for the simulation of nanoparticles propagating in the presence of fluidic and optical forces, which can be used for both optical tweezers and OF2i simulations. We demonstrate the working principle at a number of selected examples and provide the simulation software as an add-on to our generic Maxwell solver NANOBEM that is based on a boundary element method approach.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"24 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672770","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":"Optical Phase Conjugation of Self-Accelerating Waves","authors":"Tong Qi, Yi-Zhe Chen, Ding Yan, Xiang-Wei Wang, Wei Gao","doi":"10.1021/acsphotonics.4c02387","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02387","url":null,"abstract":"Self-accelerating waves have significantly advanced fundamental research and applications, particularly in optical communication, super-resolution imaging, and optical manipulation, owing to their unique curved propagation properties. Phase conjugation, serving as an essential technique for aberration correction, pulse compression, and optical computation, plays a crucial role in applications involving self-accelerating waves. Among various phase conjugation mechanisms, stimulated Brillouin scattering (SBS) mediated by light-sound interactions stands out as a promising approach. Here, we report on the phase conjugation of self-accelerating waves utilizing cross-pump-focused SBS geometry. This study demonstrates wavefront and Poynting vector reversals, achieving time-reversed propagation along diverse curved trajectories. The reversed energy flow, induced by Poynting vector conjugation, can be controlled by manipulating the original wave characteristics and propagation conditions. The distortion compensation is implemented during the propagation of self-accelerating waves through anisotropic media, demonstrating robust wavefront restoration capabilities. This proof-of-concept work opens avenues for innovative applications in structured photonics, expanding the utility of self-accelerating waves in emerging technologies.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"22 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666712","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":"Detecting Hot Electron-Induced Local Damage Using THz Near-Field Optical Microscopy","authors":"Weijie Deng, Yinan Wang, Xiaoyan Zhu, Rui Xin, Tianxin Li, Qianchun Weng, Wei Lu","doi":"10.1021/acsphotonics.5c00108","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c00108","url":null,"abstract":"Hot electron-induced degradation in semiconductor devices is a critical factor affecting the reliability and performance of microelectronic systems. While existing techniques provide valuable insights into post-failure analysis, directly visualizing hot electrons during device operation remains challenging yet essential for understanding hot electron-induced damage and degradation. In this work, we introduce ultrasensitive terahertz near-field optical microscopy to detect early-stage nanoscale damage in a GaAs/AlGaAs conducting channel with minimal conductance deviation (Δ<i>R</i>/<i>R</i> = 2.5%) by measuring hot electron-associated photon emission. Prolonged hot electron stress leads to the formation of surface lattice cracks that propagate along specific crystal orientations, underscoring the role of the hot electron in accelerating device degradation. Complementary Joule heat simulations show that lattice heating has a negligible effect on failure, supporting the conclusion that hot electron-induced effects dominate the degradation process. Our findings offer new insights into the mechanisms of hot electron-induced damage and demonstrate the terahertz nanoimaging technique as an effective tool for studying reliability issues in semiconductor devices, potentially aiding in the development of more resilient microelectronic systems.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"3 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666713","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":"High Repetition Rate and High Energy Ultrashort Laser Pulse: The Next Light Source for Attosecond Spectroscopy","authors":"Yuan Kang, Xuhan Wang, Longhua Tang, Xu Liu, Xiaochun Gong","doi":"10.1021/acsphotonics.4c01896","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01896","url":null,"abstract":"The ultrashort femtosecond laser pulse techniques in Ti:Sapphire laser systems advanced the development of attosecond pulse generation and associated attosecond metrology in probing attosecond time-resolved electron motion in atoms, molecules, and condensed matter. However, the limitation of its average power, repetition rate, and pulse energy leads to a bottleneck in developing high-flux and high-energy attosecond light sources. The recent breakthroughs in nonlinear spectral broadening have unlocked the potential for extending Yb-doped lasers to generate high-flux and high-repetition-rate attosecond extreme ultraviolet (EUV) pulses. Here, we briefly summarized the development of postpulse compression methods of the multithin plate (MTP) and multipass cell (MPC), which have shown significant advancements in achieving a high-average-power ultrafast laser. The advanced ultrafast light sources provide more choices on the applications for fundamental research within extreme temporal and spectral scales, of which the advantages are paving the way for novel discoveries in ultrafast science and promoting the research in attosecond coincidence spectroscopy, tabletop attosecond soft X-ray spectroscopy, and attosecond EUV nanoimaging and, consequently, opening the avenue to realize a breakthrough in zeptosecond time resolution and even zeptosecond pulse generation.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"6 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672771","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":"Long-Range and Dead-Zone-Free Dual-Comb Ranging for the Interferometric Tracking of Moving Targets","authors":"Sandro L. Camenzind, Lukas Lang, Benjamin Willenberg, Justinas Pupeikis, Hayk Soghomonyan, Robert Presl, Pabitro Ray, Andreas Wieser, Ursula Keller, Christopher R. Phillips","doi":"10.1021/acsphotonics.4c02199","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02199","url":null,"abstract":"Dual-comb ranging has emerged as an effective technology for long-distance metrology, providing absolute distance measurements with high speed, precision, and accuracy. Here, we demonstrate a dual-comb ranging method that utilizes a free-space transceiver unit, enabling dead-zone-free measurements and simultaneous ranging with interchanged comb roles to allow for long-distance measurements, even when the target is moving. It includes a graphics processing unit (GPU)-accelerated algorithm for real-time signal processing and a free-running single-cavity solid-state dual-comb laser with a carrier wavelength λ_c ≈ 1055 nm, a pulse repetition rate of 1 GHz, and a repetition rate difference of 5.06 kHz. This combination offers a fast update rate and sufficient signal strength to reach a single-shot time-of-flight precision of around 0.1 μm (i.e., &lt;λ_c/4) on a cooperative target placed at a distance of more than 40 m. The free-running laser is sufficiently stable to use the phase information for interferometric distance measurements, which improves the single-shot precision to &lt;20 nm. To assess the ranging accuracy, we track the motion of the cooperative target when moved over 40 m and compare it to a reference interferometer. The residuals between the two measurements are below 3 μm. These results highlight the potential of this approach for accurate and dead-zone-free long-distance ranging, supporting real-time tracking with nm-level precision.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"27 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143672772","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":"Ultracompact Spatial Speckle Reconstructive Spectrometer Based on a Waveguide Corner with Chaotic Reflection","authors":"Zhipeng Guo, Long Zhang, Daoxin Dai","doi":"10.1021/acsphotonics.4c02401","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02401","url":null,"abstract":"On-chip spectrometers offer significant advantages in terms of compactness and portability, paving the way for advancements in both industrial applications and scientific research. The growing demand for high-performance and miniaturized spectral sensing modules is particularly evident in applications such as smartphones and wearable sensors. In this paper, we introduce and demonstrate an ultracompact and high-performance spatial speckle reconstructive spectrometer, which utilizes chaotic reflection achieved with a waveguide corner consisting of a randomly rough reflecting facet, resulting in chaotic spectral responses at multiple output ports within an ultracompact footprint. Additionally, we propose the concept of segmenting and switching the working window to enable enhanced spectral resolution by sacrificing a certain amount of working bandwidth. This also facilitates the combination of multiple sub-bands to achieve both high resolution and broad bandwidth. We combine innovative schemes and a convex optimization algorithm, leading to a remarkable resolution of 0.02 nm for the spectral range of 1520–1610 nm even with an ultracompact size of 250 μm² for the fabricated chip. To the best of our knowledge, the present spatial-domain speckle reconstructive spectrometer shows the highest channel-number-to-footprint ratio (λ_bandwidth/(λ_res·footprint)) of up to 1.8 × 10⁷ mm^–2, offering a promising option for on-chip spectral analysis.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"56 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660875","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":"Cavity-Enhanced Acousto-Optic Modulators on Polymer-Loaded Lithium Niobate Integrated Platform","authors":"Zhi Jiang, Danyang Yao, Yu Gao, Xu Ran, Jianguo Wang, Xuetao Gan, Yan Liu, Yue Hao, Genquan Han","doi":"10.1021/acsphotonics.4c02302","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c02302","url":null,"abstract":"On-chip acousto-optic (AO) modulation represents a significant advancement in the development of highly integrated information processing systems. However, conventional photonic devices face substantial challenges in achieving efficient conversion due to the limited overlap between acoustic waves and optical waves. In this study, we address this limitation by demonstrating an enhanced conversion effect of photonic crystal nanobeam cavity (PCNBC) in AO modulation on a polymer-loaded lithium niobate integrated platform. Attributed to the high quality factor to mode volume ratio (<i>Q</i>/<i>V</i>) and optimal light-sound overlap within the nanocavity, PCNBC-based AO modulator exhibits a significantly enhanced extinction ratio of 38 dB with a threshold RF power below −50 dBm, which is two orders of magnitude lower than that based on microring resonator (MRR). In addition, robust digital amplitude shift keying modulations were performed using selected RF and optical channels of the PCNBC-enhanced AO modulators. These findings validate the compelling properties of the PCNBC photonic platform, establishing it as a promising candidate for on-chip integrated microwave photonics, optical transceivers, and computing applications.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"15 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666714","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}