Applied optics最新文献_第2页

Fabry-Perot interferometric humidity sensor based on PVA-GQDs composite film. 基于PVA-GQDs复合膜的法布里-珀罗干涉式湿度传感器。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-21 DOI: 10.1364/AO.613590

Gao Zeng, Chengju Ma, Xiaolong Huang, Ziyi Zhang, Dongning Li, Wei Fan, Juanni Li, Yang Wang

引用次数: 0

Range expansion of FMCW LiDAR by using a swept optical frequency comb and phase noise compensation. 采用扫频光梳和相位噪声补偿的FMCW激光雷达范围扩展。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-22 DOI: 10.1364/AO.609482

Takahiro Nagata, Yuto Kusaka, Chao Zhang, Fumihiko Ito, Shingo Ohno, Atsushi Nakamura, Kunihiro Toge

{"title":"Range expansion of FMCW LiDAR by using a swept optical frequency comb and phase noise compensation.","authors":"Takahiro Nagata, Yuto Kusaka, Chao Zhang, Fumihiko Ito, Shingo Ohno, Atsushi Nakamura, Kunihiro Toge","doi":"10.1364/AO.609482","DOIUrl":"https://doi.org/10.1364/AO.609482","url":null,"abstract":"In frequency-modulated continuous-wave (FMCW) ranging, there exist fundamental limitations on the measurement distance, refresh rate, and depth resolution imposed by the bandwidth of the photodetector. In addition, the coherence of the light source degrades interferometric performance in long-range measurements, thereby constituting another limiting factor on the achievable measurement distance. In this paper, we propose a wavelength-swept optical frequency comb-based approach to overcome the bandwidth-imposed limitation. Furthermore, by applying a phase noise compensation (PNC) method originally developed for optical frequency domain reflectometry (OFDR), the coherence-related limitation is simultaneously mitigated, enabling long-range and high-precision FMCW LiDAR. The theoretical framework of the proposed scheme is presented, and proof-of-principle experiments under fiber-emulated long-delay conditions are performed to demonstrate mitigation of the bandwidth limitation using a wavelength-swept frequency comb with three discrete frequency components. In addition, the coherence-limited range is extended to 12 times that achievable with conventional FMCW schemes.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"65 29","pages":"10306-10313"},"PeriodicalIF":0.0,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-bandwidth tracking control for visual servo gimbals using phase-compensated Youla parameterization with time delay. 带时滞的相位补偿Youla参数化视觉伺服框架高带宽跟踪控制。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-25 DOI: 10.1364/AO.612280

Jiayu Hu, Wenqin Ding, Tao Tang

{"title":"High-bandwidth tracking control for visual servo gimbals using phase-compensated Youla parameterization with time delay.","authors":"Jiayu Hu, Wenqin Ding, Tao Tang","doi":"10.1364/AO.612280","DOIUrl":"https://doi.org/10.1364/AO.612280","url":null,"abstract":"This paper proposes a phase-compensated high-order Youla-Kucera (HYK) parameterization method to achieve high-bandwidth tracking control for CCD-based visual servo gimbals under sparse sampling and image time delays. The proposed HYK method develops a novel, to our knowledge, high-order low-pass filter topology that actively reshapes the internal YK branch. By analytically compensating for the phase lag intrinsically introduced by the filtering dynamics, the HYK method permits a substantial extension of the effective Q-filter bandwidth without violating the small-gain stability criterion or amplifying high-frequency measurement noise. A rigorous frequency-domain loop-shaping analysis reveals that the introduced feedforward polynomial injects dynamic complex zeros into the open-loop transfer function, actively shifting the phase trajectory near crossover and thereby preserving adequate stability margins under increased bandwidth conditions. Experimental results on a dual-axis inertial gimbal testbed indicate that the proposed method can be easily implemented and exhibits excellent performance in tracking accuracy and disturbance rejection.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"65 29","pages":"10336-10343"},"PeriodicalIF":0.0,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149228915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical study of a tunable graphene terahertz absorber with an asymmetric ring-comb metasurface. 具有不对称环梳超表面的可调谐石墨烯太赫兹吸收体的数值研究。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-23 DOI: 10.1364/AO.607762

Le Zhang

{"title":"Numerical study of a tunable graphene terahertz absorber with an asymmetric ring-comb metasurface.","authors":"Le Zhang","doi":"10.1364/AO.607762","DOIUrl":"https://doi.org/10.1364/AO.607762","url":null,"abstract":"A tunable terahertz absorber based on a comb-integrated asymmetric ring graphene metasurface is numerically investigated. The device has a compact trilayer configuration consisting of monolayer graphene, a SiO2 spacer, and an Au back reflector. When the graphene Fermi level increases from 0.5 to 1.0 eV, the main absorption peak moves from 1.052 to 1.492 THz, corresponding to a 0.440 THz shift; the peak absorptance remains above 90% and ranges from 91.54% to 99.52% for the five sampled states. The magnetic-field distributions show a coupled response of the asymmetric outer ring and the inner comb-like branches. The outer ring provides the main resonant path, whereas the comb branches introduce local coupling and field confinement. The Au back reflector suppresses transmission, and the SiO2 spacer contributes the cavity phase required to reduce reflection. Parametric simulations show that changes in wline, Rin, and Rout mainly alter the resonance frequency and spectral line shape. Under oblique incidence, identifiable absorption bands remain for both TE and TM excitation, although their angular evolution differs. These results show that a single patterned graphene layer can electrically reposition a high-absorption resonance within 1-2 THz.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"65 29","pages":"10324-10331"},"PeriodicalIF":0.0,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Time-resolved measurement of simulated methane emissions from livestock, using wavelength modulation spectroscopy. 利用波长调制光谱学对家畜模拟甲烷排放进行时间分辨测量。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-15 DOI: 10.1364/AO.604737

Brian J Orr, Yabai He, Julian Hill

引用次数: 0

Simultaneous observation of tropospheric O₃ and volcanic SO₂ using a three-wavelength differential absorption lidar based on a Nd:YAG laser and a CO₂ Raman cell. 基于Nd:YAG激光器和CO2拉曼电池的三波长差分吸收激光雷达对流层O3和火山SO2的同步观测

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-15 DOI: 10.1364/AO.606751

Masahisa Nakazato, Tomohiro Nagai, Tetsu Sakai, Osamu Uchino

{"title":"Simultaneous observation of tropospheric O3 and volcanic SO2 using a three-wavelength differential absorption lidar based on a Nd:YAG laser and a CO2 Raman cell.","authors":"Masahisa Nakazato, Tomohiro Nagai, Tetsu Sakai, Osamu Uchino","doi":"10.1364/AO.606751","DOIUrl":"https://doi.org/10.1364/AO.606751","url":null,"abstract":"We present a three-wavelength differential absorption lidar (DIAL) method for the simultaneous retrieval of tropospheric ozone (O3) and sulfur dioxide (SO2). The system employs a single Nd:YAG laser and a carbon dioxide (CO2) Raman cell to generate three ultraviolet laser wavelengths at 276, 287, and 299 nm. The number densities of O3 and SO2 are simultaneously retrieved by analytically solving coupled DIAL equations using the three-wavelength observation data. In contrast to conventional two-wavelength analyses that are sensitive to the choice of wavelength pairs, the proposed three-wavelength approach yields consistent retrieval results regardless of the wavelength combinations in the case where absorption cross sections are known. Spectrum factor calculations demonstrate that the three wavelengths generated by stimulated Raman scattering (SRS) in CO2 comprise one of the most suitable wavelength sets for accurate differential absorption measurements using Nd:YAG laser harmonics. Although the system is not optimized for routine monitoring of background SO2 at typical environmental pollution levels, it detected volcanic SO2 at concentrations much lower than the human odor threshold. Lidar observations in Tsukuba successfully detected SO2 plumes transported from Mt. Asama and Mt. Oyama (Miyake Island), Japan. Thus, the proposed three-wavelength DIAL method provides increased measurement capability to the existing O3 DIAL system by extending its application to the simultaneous observation of tropospheric O3 and advected volcanic SO2 over the height range of 0.4-4 km without additional laser sources.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"65 29","pages":"10128-10142"},"PeriodicalIF":0.0,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Data-driven spatial reference construction for deviation magnification of complex edge structures. 复杂边缘结构偏差放大的数据驱动空间参考构造。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-14 DOI: 10.1364/AO.609972

Dashan Zhang, Mengjing Shi, Yuwei Wang, Jie Guo

{"title":"Data-driven spatial reference construction for deviation magnification of complex edge structures.","authors":"Dashan Zhang, Mengjing Shi, Yuwei Wang, Jie Guo","doi":"10.1364/AO.609972","DOIUrl":"https://doi.org/10.1364/AO.609972","url":null,"abstract":"Deviation magnification can reveal subtle geometric departures of structural edges, but its performance depends strongly on the definition of the spatial reference. Existing reference definitions are usually limited to predefined parametric geometries or spatial recurrence assumptions. This paper proposes a data-driven spatial reference construction method based on second-order principal-curve estimation by local means (PCLM) for complex edge structures. The surrogate reference is constructed directly from the observed edge points without requiring a predefined global geometry, spatial recurrence, or access to the true reference curve. In the proposed method, the local linear model of PCLM is extended to a local quadratic model to represent smoothly curved reference trends, while observable scale-dependent indicators are introduced to constrain the neighborhood size. The constructed reference provides a geometrically consistent spatial baseline for normal-deviation extraction and visual magnification. Simulations and real experiments on PVC pipe vibration and lattice structure stretching validate the effectiveness of the proposed method for both simple closed boundaries and complex multi-edge structures.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"65 29","pages":"10065-10075"},"PeriodicalIF":0.0,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Non-volatile reflective displays based on ultrathin GeTe phase-change layers. 基于超薄GeTe相变层的非易失性反射显示器。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-22 DOI: 10.1364/AO.613347

Jiao Zhou, Ming Liu, Cong Qiu, Shiguo Li

{"title":"Non-volatile reflective displays based on ultrathin GeTe phase-change layers.","authors":"Jiao Zhou, Ming Liu, Cong Qiu, Shiguo Li","doi":"10.1364/AO.613347","DOIUrl":"https://doi.org/10.1364/AO.613347","url":null,"abstract":"Phase-change materials provide a promising approach for reflective displays with persistent optical states. However, single-layer devices often face challenges in simultaneously achieving high optical contrast, reliable phase stability, and effective primary-color generation. Here, rather than proposing a new cavity topology, we use the established Pt/ITO/PCM/ITO asymmetric Fabry-Pérot configuration as a controlled platform to establish design rules for a single fixed-thickness PCM active layer. This objective differs from the dual-GeTe reflector reported in Ref. [Adv. Opt. Mater.7, 1801214 (2019)], which employed two GeTe layers with thickness-dependent crystallization temperatures to enable selective switching and multiple color states using a single heater. By comparing GST, GeTe, and Sb2Te3 under identical optical boundary conditions, we evaluate the combined effects of phase-change modulation, optical loss, usable ultrathin thickness range, and reported phase stability. Layer-resolved absorption and electric-field analyses further distinguish the functions of the PCM and the bottom ITO spacer. Together, these findings establish a transferable design sequence: select the PCM according to the modulation-loss-stability trade-off, determine its thickness by balancing optical-field interaction against dissipative loss, and then tune the spacer optical thickness to position the desired spectral channel. Following this sequence, GeTe was selected for the present devices under the investigated conditions.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"65 29","pages":"10356-10363"},"PeriodicalIF":0.0,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-temperature reliability of AlGaN deep-UV light-emitting diodes for extreme environments. AlGaN深紫外发光二极管在极端环境下的高温可靠性

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-07-09 DOI: 10.1364/AO.607587

Swetha Velpula, Mano Bala Sankar Muthu, Ravi Teja Velpula, Injamamul Hoque Emu, Tamara Faranaz Ena, Hoang-Duy Nguyen, Hieu Pham Trung Nguyen

引用次数: 0

Small-diameter pipeline panoramic measurement system based on dual-view acquisition and valid information recovery. 基于双视点采集和有效信息恢复的小口径管道全景测量系统。

Applied optics Pub Date : 2026-10-10 Epub Date: 2026-09-15 DOI: 10.1364/AO.607584

Haokai Wu, Jiehu Kang, Xiaolong Yang, Ziran Feng, Yunju Bai, Zongyang Zhao, Yichen Xu, Bin Wu

{"title":"Small-diameter pipeline panoramic measurement system based on dual-view acquisition and valid information recovery.","authors":"Haokai Wu, Jiehu Kang, Xiaolong Yang, Ziran Feng, Yunju Bai, Zongyang Zhao, Yichen Xu, Bin Wu","doi":"10.1364/AO.607584","DOIUrl":"https://doi.org/10.1364/AO.607584","url":null,"abstract":"Small-diameter pipes have been widely used in various industrial fields, but achieving imaging with both high quality and high efficiency in such a confined space remains a challenging problem. To address this issue, a visual measurement system based on a conical mirror and an object-space telecentric lens is designed and implemented. To overcome information loss caused by annular image compression and occlusion from structural support pillars, an acquisition strategy combining axial multi-frame stitching and dual-view image complementarity is proposed to acquire raw images. Together with corresponding image processing procedures, the resulting image that contains complete information about inner wall morphology is obtained. Experimental results on defect size measurement show that, compared with the ground truth, the proposed system achieves a maximum absolute deviation of 57 µm and an average absolute deviation of 34 µm. In addition, the system is applicable to inner wall topography measurement of pipes made of different materials, thereby demonstrating the engineering practicality of the proposed approach.","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"65 29","pages":"9996-10005"},"PeriodicalIF":0.0,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149229672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0