Optics letters最新文献

{"title":"Highly pure electric-field skyrmions from a zonally modulated metasurface.","authors":"Lingxing Xiao, Pusheng Liu, Yanlin Wang, Qing Zhang, Yuanjie Yang","doi":"10.1364/OL.611691","DOIUrl":"https://doi.org/10.1364/OL.611691","url":null,"abstract":"<p><p>Optical skyrmions are widely investigated in topological photonics, yet generating their vector textures in three dimensions purely within the electric field remains a challenge. Here, we show that a single-layer dielectric metasurface can overcome this constraint through a zonal modulation strategy to decouple focal field control. By using a low numerical aperture (NA) inner core largely governing the transverse field and a high-NA outer ring mainly contributing to the longitudinal field, highly pure Néel-type and Bloch-type electric field skyrmions are successfully generated. This zonal design strategy clarifies how tightly focused vector fields can be decomposed into separate transverse-texture and longitudinal-polarity functions, providing a compact route for generating electric-field skyrmions with flat optics.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5502-5505"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Single-VIPA dual-mode absorption-emission spectroscopy for plasma diagnostics.","authors":"Nianyao Guo, Dong Zhi, Jing Tu, Hufeng Liu, Yunfei Li, Long Huang, Wei Chen, Weixiong Zhao, Lunhua Deng, Sanjun Zhang","doi":"10.1364/OL.615252","DOIUrl":"https://doi.org/10.1364/OL.615252","url":null,"abstract":"<p><p>Combined absorption-emission spectroscopy is demonstrated using a single VIPA spectrometer coupled to a supercontinuum source. The system captures a ~36 nm bandwidth (742-778 nm) at picometer resolution. In a low-pressure glow discharge, N₂ emission calibration, O I 777 nm triplet absorption (2.2% consistency), and linewidth analysis distinguishing instrumental/Doppler broadening from Ar I self-absorption (broadening factors up to ~1.5) are performed. Joint retrieval of temperature (953 ± 49 K) and instrumental width, along with time-division absorption-emission measurements, is demonstrated. Long-term stability makes this approach suitable for quasi-steady plasmas.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5601-5604"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"2-photon fluorescence microscopy of brain cells beyond 2 mm.","authors":"Yingxian Zhang, Jiemei Yan, Zhenhui Li, Chi Zhang, Jie Huang, Sijia Tang, Yuhuan Li, Xiaoyang Ye, Jinfeng Liu, Ping Qiu, Ke Wang","doi":"10.1364/OL.606359","DOIUrl":"https://doi.org/10.1364/OL.606359","url":null,"abstract":"<p><p>3-photon microscopy (3 PM) has been the dominant technology for in vivo imaging of deep brain cells down to the hippocampus. However, tissue attenuation and rapid 3 PM signal decay limit the imaging depth to 1.5 mm. Here, we demonstrate non-invasive 2-photon fluorescence (2PF) imaging to a depth of 2 mm in the mouse brain. Excitation in the 1700-nm window minimizes brain attenuation, while 2-photon excitation reduces signal decay compared with other multiphoton modalities. IRDye 800CW 2-DG enables brain-cell labeling and 2PF excitation in this window. Its 2PF emission extends into the NIR-II region, enabling NIR-II 2PF imaging of brain cells. These results establish 2PF microscopy as a promising approach for deeper brain imaging.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5490-5493"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Soliton families in the complex square lattice with double spatial symmetry.","authors":"Jianwen Wu, Dumitru Mihalache, Milivoj R Belić, Qing Wang","doi":"10.1364/OL.612938","DOIUrl":"https://doi.org/10.1364/OL.612938","url":null,"abstract":"<p><p>This paper investigates soliton families in the two-dimensional Kerr nonlinear Schrödinger equation with a complex linear lattice. Two kinds of complex lattices are considered, both consisting of square unit cells and each compatible with more than one spatial symmetry. The first complex lattice exhibits one parity-time (PT) symmetry and one partial PT (PPT) symmetry, whereas the second one possesses double PPT symmetry. The band structures and linearized spectra of these two lattices display significant differences. In the presence of self-focusing nonlinearity, multiple types of solitons are found within the semi-infinite band gaps. The stability of these localized gap modes is examined using two numerical approaches: linear stability analysis and direct perturbed simulations. The results indicate that all solitons possess stable regions within the first complex square lattice, whereas they are all unstable in the second complex lattice. This instability is attributed to the more intricate imaginary part, leading to the appearance of nonzero real parts in their stability eigenvalue spectra.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5593-5596"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Ambient-stable Mg²⁺-doped Cs₃Cu₂I₅ nanocrystals with enhanced photoluminescence for color conversion blue LEDs: erratum.","authors":"Xuanming Zhang, Yang Tang, Chenfeng Lin, Hao Xie, Ronglei Fan, Dongdong Yan, Xiaoyu Wang, Yongfeng Liu, Weixiang Ye","doi":"10.1364/OL.618316","DOIUrl":"https://doi.org/10.1364/OL.618316","url":null,"abstract":"<p><p>We present an erratum to our Letter [Opt. Lett.50, 3840 (2025)10.1364/OL.560908] and correct several labeling and presentation errors in Fig. S3(a), Table S1, and the corresponding description in the main text. These corrections do not affect the experimental results or scientific conclusions of the original Letter.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5571-5572"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"MZI-switched dual-input SOI-AWG interrogator for neural-network-assisted FBG interrogation.","authors":"Qichao Wang, Jingzhou Sun, Zixiao Zhu, Binfeng Yun, Guohua Hu, Yiping Cui","doi":"10.1364/OL.612115","DOIUrl":"https://doi.org/10.1364/OL.612115","url":null,"abstract":"<p><p>A dual-input silicon-on-insulator (SOI) arrayed waveguide grating (AWG) fiber Bragg grating (FBG) interrogator, enabled by an on-chip Mach-Zehnder interferometer (MZI) switch, is proposed and experimentally demonstrated. The device integrates a polarization beam splitter (PBS), a thermo-optic MZI, and an asymmetric dual-input AWG. The MZI enables on-chip selection of two AWG input ports, generating complementary spectral responses without increasing the number of output channels. Due to fabrication-induced non-idealities in SOI-AWG responses, conventional fitting-based interrogation methods suffer from increased errors. A feature-engineered feedforward neural network (FNN) is developed by exploiting multichannel responses from the two input states. Experimental results show that the proposed dual-input FNN achieves an interrogation root-mean-square error (RMSE) of 2.33 pm on an independent external test set, reducing the error from 8.06 pm obtained by polynomial fitting. This work provides a compact and high-precision solution for on-chip FBG interrogation.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5585-5588"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Spatially or temporally resolved phase-based optoretinography with actively tracked point-scanning optical coherence tomography.","authors":"Léo Puyo, Jonas Franke, Felix Zeisberger, Roland Rocholz, Gereon Hüttmann","doi":"10.1364/OL.606323","DOIUrl":"https://doi.org/10.1364/OL.606323","url":null,"abstract":"<p><p>Optoretinography is a promising approach to measure visual function, but its clinical translation has remained confined to research settings due to demanding hardware requirements. Here, we demonstrate that high-quality phase-based optoretinography can be performed using conventional point-scanning spectral-domain optical coherence tomography. We show that the need for high imaging speed can be circumvented by accurate sampling of phase changes at a consistent spatial location. Light-evoked outer-segment expansion could be temporally resolved in B-scan series acquired at a fixed position when filtering out-of-location B-scans and spatially resolved in volumes acquired at rates as low as 1 Hz. These results indicate that the technical barrier for phase-based optoretinography is substantially lower than was previously assumed and pave the way toward broad clinical translation.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5361-5364"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"All-fiber delivery of 1.3 kW laser power through a hollow-core anti-resonant fiber with a 14 μm mode field diameter.","authors":"Weiqing Gao, Tianhao Hu, Lu Dai, Ziqi Zheng, Haitao Tan, Jiayi Liu, YiFei Xu, Jun Chu, Lei Zhang, Yong Zhou","doi":"10.1364/OL.615858","DOIUrl":"https://doi.org/10.1364/OL.615858","url":null,"abstract":"<p><p>Hollow-core anti-resonant fibers (HC-ARFs) provide an attractive platform for high-power laser delivery because most of the optical field propagates in air, enabling high damage thresholds, weak light-silica interaction, and low optical nonlinearity. Here, we demonstrate all-fiber delivery of 1338 W continuous-wave laser power through a 2-m HC-ARF with a 14-µm mode-field diameter and a coupling efficiency of 97.1%. Efficient coupling is achieved by fusion splicing a mode-matched solid-core delivery fiber to the HC-ARF with an anti-reflection-coated end face and optimized offset-arc parameters. The fiber shows negligible bend-induced loss for bend diameters down to 13 cm, supporting compact and flexible deployment. Furthermore, the system enables passive beam cleaning, improving the beam quality factor (M²) from 1.25 to 1.15 via the preferential attenuation of higher-order modes. This compact all-fiber HC-ARF system combines a small mode field, kilowatt-level power density, and near-diffraction-limited beam quality, offering stable and flexible delivery of high-quality beams.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5637-5640"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149112881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"PMN-PT nanocrystal composite optical fibers with enhanced nonlinear response.","authors":"Min Sun, Zhe Zhu, Yuli Pang, Yunxiang Ma, Xu Lu, Gang Yuan, Ziheng Miao, Yin Wu, Wei Lin, Ruoyu Xiao, Qingyuan Hu, Qi Qian, Fei Li, Xiaoyong Wei, Zhuo Xu","doi":"10.1364/OL.611967","DOIUrl":"https://doi.org/10.1364/OL.611967","url":null,"abstract":"<p><p>Ferroelectric crystal materials constructed into one-dimensional optical fibers are attractive for optoelectronic applications. However, the development of ferroelectric optical fibers has been constrained by fabrication challenges, particularly the integration of a high-refractive-index ferroelectric crystal core with a low-refractive-index glass cladding. In this paper, PMN-PT nanocrystal composite optical fibers are drawn from a fiber preform combining a PMN-PT single-crystal rod into a silica glass tube, using a melt-in-tube method. The as-drawn fibers comprise a silica cladding and a coral-shaped core of PMN-PT nanocrystals embedded in a silica matrix. These PMN-PT nanocrystal composite optical fibers exhibit a graded-index optical waveguide characteristic and a high third-order nonlinear coefficient (approximately one hundred times higher than that of silica photonic crystal fibers), enabling broadband nonlinear wavelength conversion.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5617-5620"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Monolithic tantalum pentoxide athermal microrings with intrinsic Q factors exceeding 5 × 10⁶ without SiO₂ cladding.","authors":"Xinzhi Zheng, Yixuan Yang, Renhong Gao, Lingling Qiao, Jintian Lin, Ya Cheng","doi":"10.1364/OL.608702","DOIUrl":"https://doi.org/10.1364/OL.608702","url":null,"abstract":"<p><p>Tantalum pentoxide (Ta₂O₅), as a silicon-photonic-compatible material platform, has garnered significant attention for high-performance wafer-scale integrated photonics due to its exceptional properties: a broad transparency window spanning from 0.28 µm to 8 µm, a moderate refractive index of 2.05 at 1550 nm, an impressive nonlinear refractive index of 1.0 × 10^-14 cm²/W, and thick-film deposition with low residual stress at room-temperature. Despite these advantages, achieving low-loss fabrication of monolithic microrings on the Ta₂O₅ platform remains challenging due to its inherent hardness and brittleness, which often result in rough sidewalls and significant scattering losses. In this work, we successfully demonstrated monolithic Ta₂O₅ microring resonators with exceptionally high intrinsic and loaded quality (Q) factors, without covering with SiO₂ cladding to preserve its intrinsic material properties. This was accomplished through the innovative application of photolithography-assisted chemo-mechanical etching (PLACE) technique for producing the device with an ultra-smooth surface. By optimizing the coupling region between the microring and the bus waveguide, near-critical coupling was achieved. The device exhibited loaded Q factors of 3.89 × 10⁶ in the telecom band without employing expensive electron-beam lithography, showing an intrinsic Q factor as high as 5.49 × 10⁶ and a low propagation loss of only 0.0696 dB/cm-representing the highest results reported for strongly confined Ta₂O₅-based microrings to date. Moreover, the suppressed temperature-induced resonant wavelength shift rate of only 9 pm/°C was also demonstrated, showing impressive thermal stability. This work paves the way for the development of advanced photonic devices on the Ta₂O₅ platform with low manufacturing cost, including low-threshold microlasers, highly sensitive sensors, broad-bandwidth supercontinuum sources, and optical frequency combs.</p>","PeriodicalId":19540,"journal":{"name":"Optics letters","volume":"51 19","pages":"5437-5440"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}