Optics express最新文献

{"title":"Modeling of single-scatter NLOS/LOS ultraviolet communication channels based on threshold sphere and performance analysis in mobile scenarios.","authors":"Rui Hao, Jianping Wang, Danyang Chen, Huimin Lu, Jianli Jin","doi":"10.1364/OE.571643","DOIUrl":"https://doi.org/10.1364/OE.571643","url":null,"abstract":"<p><p>Based on the scattering characteristics of ultraviolet light, the existing studies on ultraviolet communication (UVC) channels mainly focus on non-line-of-sight (NLOS) links, but lack research on line-of-sight (LOS) links. In this paper, a single-scatter sphere-threshold-based NLOS/LOS UVC channel model is proposed by introducing an imaginary threshold ball. The analytical expressions for the path loss (PL) of the LOS link and the whole link are derived. The simulation results demonstrate that the proposed model aligns closely with the Monte Carlo model, and in the presence of LOS links, its root mean square error (RMSE) is only 0.1138 dB. Further, the expressions for the PL and the channel impulse response (CIR) when the receiver is moving are derived, and the impact of parameters such as motion speed and motion direction is systematically analyzed. The results show that the PL and the CIR are more sensitive to the coplanar-noncoplanar transition (CNT) when the transmitter and receiver are close to a coplanar state at the initial time. In addition, the distance between the transmitter and receiver is the dominant factor affecting channel performance in all scenarios.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"37697-37717"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125717","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":"High sensitivity all-sapphire fiber diaphragm-based extrinsic Fabry-Perot interferometric pressure sensor for ultra-high temperature environments.","authors":"Shuang Zhao, Yi Jiang, Hui Deng, Yutong Zhang","doi":"10.1364/OE.568687","DOIUrl":"https://doi.org/10.1364/OE.568687","url":null,"abstract":"<p><p>A high sensitivity all-sapphire fiber diaphragm-based extrinsic Fabry-Perot interferometer (EFPI) is proposed for pressure measurement in ultra-high temperature environments. The sensor is fabricated by directly bonding three polished sapphire wafers, forming the composite Fabry-Perot (FP) structure to simultaneously measure pressure and temperature. The demodulation accuracy is improved due to the polished sapphire wafers with low surface roughness. The sapphire fiber is adopted to pick up the sensing signals, effectively increasing the operating temperature of the sensing structure. Experimental results show that the sensing structure can work stably within the pressure range of 0 kPa to 300 kPa and the temperature range of 20 °C to 1415 °C. The optical cavity length (OCL) of the air cavity varies linear with pressure, and the pressure sensitivity increases from 17.02 nm/kPa at room temperature to 22.34 nm/kPa at 1415 °C. Based on its excellent performance, the proposed sensing structure is prospective for accurate pressure measurement in harsh environments.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"37322-37333"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125719","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":"Advantages of random lasers in high-resolution speckle-free bio-imaging.","authors":"Yuan Wan, Liming Gao, Zhihao Li, Zhaopeng Xu, Xu Han, Yangjian Cai, Jianghao Li","doi":"10.1364/OE.572707","DOIUrl":"https://doi.org/10.1364/OE.572707","url":null,"abstract":"<p><p>Random lasers, which bridge the gap between the conventional light-emitting diodes (LEDs) and coherent laser diodes (LDs), have been proven as promising light sources to suppress speckle patterns in optical imaging. In this study, to explore the potential of random lasers for speckle pattern suppression within bio-imaging, we designed a random laser based on a gold (Au)/graphene hybrid structure, with its emission guided by an optical fiber into the microscope system. The suppression performance of the speckle patterns in scattering environments has been systematically investigated. Our experimental results show that the sharpness factors of the images can be improved significantly, and therefore, higher-resolution images with suppressed speckle patterns can be obtained in scattering environments with the help of the proposed random laser. Moreover, we demonstrated that compared to conventional lasers, random lasers have significant advantages in obtaining high-resolution speckle-free bio-imaging. This study confirms the significant potential of random lasers in bio-imaging, minimally invasive medicine, and damage detection.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"37982-37989"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125742","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":"Light-trapping by wave interference in intermediate-thickness silicon solar cells: reply.","authors":"Sayak Bhattacharya, Sajeev John","doi":"10.1364/OE.559449","DOIUrl":"https://doi.org/10.1364/OE.559449","url":null,"abstract":"<p><p>We identify and discuss incorrect assertions, misrepresentations, and various speculations, presented in the Comment [Opt. Express3337499202510.1364/OE.546086] about our numerical calculations and related experimental measurements. A typographical error in our original manuscript has also been identified. We provide specific evidence that only very low relative intensities of trapped light remain in the photonic crystal, without absorption, at the time of our numerical FDTD convergence plateau. We delineate the extent of MAPD overestimation in the 1100 nm to 1200 nm wavelength range with our own direct comparison of COMSOL FEM and FDTD calculations. We also discuss sources of variance between experimental EQE and absorbance, and calculated absorption spectra.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"37503-37506"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125751","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":"Contour optimization of triangular Laue bent crystal for low wavefront distortion applications.","authors":"Mingjie Chen, Longkun Huo, Xin Yan, Xiaoxiao Liang, Fugui Yang, Xiaowei Zhang, Weifan Shenga","doi":"10.1364/OE.570547","DOIUrl":"https://doi.org/10.1364/OE.570547","url":null,"abstract":"<p><p>Crystal bending is widely used in high-energy beamlines for X-ray monochromatisation and focusing. In this research, we propose a wavefront-preserved bending design by changing the section width distribution of the triangle-bent crystal. By developing a theoretical model for the bending of triangular crystals and introducing an iterative approach based on the relationship between the crystal width profile and the bending surface, surface shape accuracy is enhanced over the pre-optimization stage. The simulation findings demonstrate that this method can greatly minimize meridian slope errors within the extended two-dimensional region while also improving the operational dynamic range of the crystal when compared to traditional triangularly bent crystals. In addition, we have investigated the crystal surface properties of the corresponding bending radii under various bending forces. Even incorporating crystal profile defects resulting from standard fabrication errors can also achieve the goal of this design. The verification results obtained using the offline experimental apparatus reveal that the optimized crystal bending system performs significantly better than the pre-optimization scheme in terms of bending accuracy. We confirm the excellent performance and feasibility of our improved bent crystal architecture.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"37641-37653"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125513","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":"Compensating spatial information loss caused by dynamic eye pupil sampling in holographic near-eye displays via time-multiplexing.","authors":"Yue Wang, Yuan Liu, Li Liang, Qibin Feng, Guoqiang Lv, Zi Wang","doi":"10.1364/OE.569639","DOIUrl":"https://doi.org/10.1364/OE.569639","url":null,"abstract":"<p><p>In holographic near-eye displays, dynamic eye pupil sampling causes spatial information loss, which leads to low quality of the observed holographic image. To address this, we propose a hologram optimization method that combines time multiplexing with random pupil mask sampling. First, the time multiplexing was incorporated into the hologram optimization and reconstruction processes, thereby enabling compensation of missing spatial information from the time dimension. Second, 1,000 randomly generated pupil masks were integrated into the optimization algorithm of the hologram to adapt to the dynamic changes of the eye pupil. To ensure more uniform holographic image quality under dynamic pupil variations, the pupil masks were sorted in descending order of diameter during the iterative process. Simulations and experiments show that the proposed method can effectively compensate for the loss of spatial information caused by pupil sampling. Moreover, when the pupil dynamically changes, a more uniform holographic image quality can be observed.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"39056-39067"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125524","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":"Origins of blue and violet luminescence in AlN films grown by MOCVD and the impact of a small amount of Ga doping.","authors":"Zhaolan Sun, Jing Yang, Yuheng Zhang, Zongshun Liu, Yufei Hou, Feng Liang, Bing Liu, Fu Zheng, Xuefeng Liu, Degang Zhao","doi":"10.1364/OE.572935","DOIUrl":"https://doi.org/10.1364/OE.572935","url":null,"abstract":"<p><p>Aluminum nitride (AlN) has attracted considerable attention for its promising applications in short-wavelength optoelectronic devices. However, undesirable blue and violet luminescence from MOCVD-grown AlN films has impeded their development. This study has experimentally investigated the blue luminescence at 2.7 eV originated from the donor-acceptor pair (DAP) transitions between V_Al acceptor and deep donors, and the violet luminescence at 3.0eVoriginated from the transitions between Al(NO_y)_x complex and conduction band or shallow donor level. Additionally, incorporating a small amount of Ga into the AlN layer during the growth can modulate the defect types and suppress violet luminescence. This study is crucial for improving the performance of AlN-based optoelectronic devices.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"38403-38412"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125529","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":"Optimization of a light field hologram via double-phase constrained spectrum tiling regularized by angular sampling.","authors":"Junjie Wei, Hongkun Cao, Xin Jin","doi":"10.1364/OE.572023","DOIUrl":"https://doi.org/10.1364/OE.572023","url":null,"abstract":"<p><p>A realistic holographic near-eye display (NED) requires uniform energy distribution within the eyebox, enabling users to have an immersive visual experience at various positions within the eyebox. However, the demand for observing low-speckle viewpoint images at different locations within the eyebox remains poorly addressed. In this study, a double-phase constrained spectrum titling encoding method is proposed for optimization of the light field hologram, which suppresses the speckle in all view images efficiently. To mitigate the uncertain effect of the perspective number of the input light field to optimization, an implicit angular sampling regulation is derived, which reversely offers the criteria for angular sampling of the holographic light field. Numerical and optical experimental results demonstrate that compared with advanced related methods, the proposed method yields reconstructed images with the least speckle noise under different pupil states, enabling users to observe high-quality corresponding viewpoint images at various positions within the eyebox.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"38573-38588"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125560","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":"Performance analysis of photon-limited PPM-FSO communications: SER under afterpulsing effect in practical photon-counting receivers.","authors":"Chen Wang, Zhiyong Xu, Jingyuan Wang, Huatao Zhu, Weifeng Mou, Jianhua Li, Jiyong Zhao, Yang Su","doi":"10.1364/OE.571463","DOIUrl":"https://doi.org/10.1364/OE.571463","url":null,"abstract":"<p><p>The optical communication system using photon-counting receivers has attracted considerable attention as it enables high-speed data transmission at extremely low average signal power. This study develops a comprehensive analytical framework for modeling the statistical behavior of practical photon-counting receivers in pulse position modulation (PPM)-free-space optical (FSO) communications. Our analysis specifically explored the impacts of the dead time, lack of photon-number-resolving capability, and non-Markovian afterpulsing effect on photon counts and yielded a closed-form approximation for the photon count probability distribution. The accuracy of the proposed model is verified against exact results obtained from Monte Carlo simulations. Furthermore, based on the proposed statistical model and the soft-decision decoding, we provide a closed-form expression for the symbol error rate of high-order PPM signals. This work provides a reliable analytical model for evaluating the performance of photon-limited PPM-FSO systems employing practical receivers.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"38352-38363"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125567","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":"Development of the operational atmospheric correction algorithm for the COCTS2 onboard the Chinese new-generation ocean color satellite.","authors":"Ruofeng Bai, Xianqiang He, Xiaomin Ye, Hao Li, Yan Bai, Chaofei Ma, Qingjun Song, Xuchen Jin, Xuan Zhang, Fang Gong","doi":"10.1364/OE.566718","DOIUrl":"https://doi.org/10.1364/OE.566718","url":null,"abstract":"<p><p>After the two operational polar-orbiting ocean color satellites HY-1C and HY-1D launched in 2018 and 2020, respectively, China launched the new-generation ocean color observation satellite (named as HY-1E or HY-3A, hereafter called HY-1E) on 16 Nov. 2023. The second-generation Chinese Ocean Color and Temperature Scanner (COCTS2), one of the major payloads onboard the HY-1E, can daily observe global ocean color and sea surface temperature. In this study, we developed operational ocean color retrieval algorithms for the HY-1E/COCTS2 and preliminarily examined their performances. Firstly, the operational atmospheric correction algorithm was established based on look-up tables generated by vector radiative transfer model for coupled ocean-atmosphere system (PCOART), and cross-calibrated by the SNPP/VIIRS-retrieved ocean color products. Then, we proposed a cross-calibration method for correcting the radiance response difference along the viewing angles, and obtained the viewing correction functions for each channel. The results showed that the determination coefficient of the linear relationship between cross-calibration simulated radiance at the top-of-atmosphere and HY-1E/COCTS2 measured radiance was larger than 0.95, indicating the good linear response of the HY-1E/COCTS2. Based on the established atmospheric correction algorithms, the HY-1E/COCTS2 data were processed to generate the daily global products of remote sensing reflectance (<i>R</i>_<i>rs</i>) and chlorophyll-a concentration (<i>Chl</i>) and were validated by the in-situ data and the synchronous products from Aqua/MODIS and SNPP/VIIRS. The mean absolute percentage errors referring to the in-situ data from AERONET-OC were 14.287% (412 nm), 13.341% (443 nm), 8.0623% (490 nm), 9.1882% (520 nm), 17.836% (565 nm), 58.474% (620 nm), 63.229% (665 nm) and 61.552% (681 nm), and the ocean color products derived by HY-1E/COCTS2 were consistent with the products from Aqua/MODIS and SNPP/VIIRS, indicating the good performance of HY-1E/COCTS2 to monitor global ocean color environment.</p>","PeriodicalId":19691,"journal":{"name":"Optics express","volume":"33 18","pages":"38029-38053"},"PeriodicalIF":3.3,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145125583","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}