Applied optics最新文献

{"title":"Phase-ReNet: a phase regression network for feature detection from a defocused pattern for camera calibration.","authors":"Wenhui Hou, Chuanqi Zhou, Haojie Zhu, Dashan Zhang, Yuwei Wang, Gao Jing, Lu Liu","doi":"10.1364/AO.564036","DOIUrl":"https://doi.org/10.1364/AO.564036","url":null,"abstract":"<p><p>Conventional camera calibration typically requires acquiring clear and focused target images for accurate feature detection. Defocused target images may reduce the feature detection accuracy and even lead to failure in estimating camera parameters. To address this issue, this paper employs the crossed fringe as a calibration pattern and develops an effective phase regression network (Phase-ReNet) for wrapped phase calibration, from which feature points can be extracted with high precision. Unlike traditional phase-shifting methods, which require multiple patterns, our method recovers horizontal and vertical phase maps using just a single pattern, significantly improving calibration efficiency. Experimental results demonstrate that this method can achieve feature detection accuracy comparable to traditional phase-shifting methods, and the mean reprojection errors of the defocused camera are only 0.0552 pixels. These results highlight that our method is suitable for defocused camera calibration tasks.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"7957-7967"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145116112","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}

{"title":"Quantum state preparation of time-bin encoding based on SOI integrated chips.","authors":"Hanming Yang, Chunxue Zhang, Pengwei Cui, Junchi Ma, Liyong Guo, Song Huang, Jianguang Li, Jiashun Zhang, Yue Wang, Xiaojie Yin, Wei Chen, YuanDa Wu, Junming An","doi":"10.1364/AO.560473","DOIUrl":"https://doi.org/10.1364/AO.560473","url":null,"abstract":"<p><p>Quantum key distribution (QKD) ensures unconditional security for public key encryption by utilizing the principles of quantum mechanics. This study designs and fabricates a QKD chip based on the silicon-on-insulator (SOI) platform, employing a time-bin encoding scheme with decoy states. In the design, we integrate a slow thermo-optic phase modulator with a carrier-depletion modulator to ensure high fidelity of quantum states and high-speed encoding capabilities, enabling precise and flexible time-bin encoding. We achieve the encoding and decoding of four BB84 quantum states at a repetition rate of 100 MHz. In the experiment, the visibility of the interference fringes for the phase state |+⟩ is 93.66%, and for the phase state |-⟩, it is 92.36%. The extinction ratios for the time states |0⟩ and |1⟩ are 19.33 and 18.72 dB, respectively. The experimental results demonstrate that the chip has efficient quantum state preparation capability, providing significant support for the practical implementation of quantum key distribution technology. Additionally, we propose a new chip structure, to our knowledge, using SOI and <i>S</i><i>i</i>₃<i>N</i>₄ heterogeneous integration. The SOI waveguide is used for high-speed modulation encoding, while the delay line is composed of <i>S</i><i>i</i>₃<i>N</i>₄ waveguides. This structure is designed to address the stability issues of the chip caused by temperature variations.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"7948-7956"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145116093","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}

{"title":"Flow-ICP: semantic segmentation of point clouds based on 4D time-series alignment.","authors":"Shuyi Tan, Chao Huang, Yi Zhang, Yang Wang","doi":"10.1364/AO.562944","DOIUrl":"https://doi.org/10.1364/AO.562944","url":null,"abstract":"<p><p>The semantic segmentation is a critical task in LiDAR point cloud processing. Leveraging temporal information to provide contextual data for regions with low visibility or sparse observations has recently become a popular research direction, especially in autonomous driving. Existing methods, however, are often over-reliant on past frames, leading to cumulative errors (drift) caused by unconstrained frame-by-frame stacking. This paper proposes a dynamic alignment of historical frame memory information to ensure consistency with the observations of the current frame, reducing deviations caused by viewpoint changes or object movements and ensuring more accurate capture of current frame features. In addition, a new multi-scale feature fusion method, to the best of our knowledge, was introduced using the spatiotemporal (ST) method to extract the ST features, which reduces the inconsistencies between 2D range image coordinates and 3D Cartesian outputs. This approach enhances feature representation by optimizing and fusing the aligned channel features. This method was evaluated on the SemanticKITTI and SensatUrban datasets. The experimental results showed that it outperforms existing state-of-the-art methods regarding accuracy.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"8068-8076"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115965","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}

{"title":"BRUCE: a metrological system for characterizing the beam-intensity rotational uniformity of side-scanning optical miniature probes.","authors":"Jin Young Youm, Joon-Mo Yang","doi":"10.1364/AO.573028","DOIUrl":"https://doi.org/10.1364/AO.573028","url":null,"abstract":"<p><p>To successfully translate optical miniature probes, such as the endoscopic miniprobe, catheter probe, and capsular probe, into clinical practice, it is essential to accurately characterize their performance and thereby precisely define the final specifications of the related device outcomes in various aspects such as biochemical, electrical, physical, mechanical, and optical aspects. Although a variety of related device concepts have been introduced in the biophotonics field in the past three decades, all the previous studies, to the best of our knowledge, focused on showcasing their biomedical potential or applications rather than developing or solidifying related metrologies to objectively characterize their performances. In this study, we developed a metrological system that can measure the beam-intensity rotational uniformity of a side-scanning optical miniature probe, regardless of its beam firing angle to the probe axis. Moreover, by applying the developed system to our photoacoustic endoscopic probe prior to conducting <i>in vivo</i> imaging experiments, we were able to confirm the beam uniformity far more accurately than was previously possible by visual inspection. In this paper, we introduce the basic concept and operating principles of the developed system and discuss the importance of characterizing the relevant beam-intensity uniformity.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"7996-8004"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115995","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}

{"title":"Self-calibration for a spatially modulated snapshot Mueller matrix imaging polarimeter.","authors":"Jing Zhang, Yangchenshu Bai, Jinfeng Tang, Yilin Zhang, Yingkai Liu, An Pan, Chenling Jia, Qizhi Cao","doi":"10.1364/AO.567593","DOIUrl":"https://doi.org/10.1364/AO.567593","url":null,"abstract":"<p><p>The self-calibration technique based on a spatially modulated snapshot Mueller matrix imaging polarimeter is proposed in this paper. Taking the snapshot Mueller matrix imaging polarimeter using modified Savart polariscopes as an example, it demonstrates that the self-calibration method can utilize frequency-domain information from independent channels to determine the spatial carrier frequency, thereby achieving frequency-domain filtering and demodulation instead of the traditional reference light calibration. This eliminates the inaccuracies introduced by the imprecise measurement of reference lights and environmental changes in the traditional calibration method, simplifies the experimental process, and removes biases caused by manual operations. The optical system design consists of two parts: the polarization state generator and the polarization state analyzer. Through the modulation of modified Savart polariscopes and half-wave plates, spatially separated interference fringes are generated. The modulation process employing Fourier transforms to the intensity of interference fringes yields 49 independent channels. Then, the demodulation process employing inverse Fourier transforms and subsequent mathematical operations on the information from each channel enables the reconstruction of 16 Mueller matrix elements. Theoretical analysis demonstrates that the system can accurately reconstruct the target's Mueller matrix using self-calibration algorithms, and its feasibility is validated through numerical simulation experiments. Experimental results show that the structural similarity index between the reconstructed images and the input target images exceeds 0.9, attaining favorable reconstruction outcomes. This technique provides a high-resolution, low-bias calibration solution for a spatially modulated snapshot Mueller matrix imaging polarimeter without using external reference lights. It holds significant application potential in biomedical science, materials research, remote sensing, and related fields.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"7968-7975"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145116106","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}

{"title":"Cascade deep polarization network for precise image semantic segmentation.","authors":"Jinyu Zhang, Xu Ma, Weili Chen, Hantang Chen, Gonzalo R Arce","doi":"10.1364/AO.561465","DOIUrl":"https://doi.org/10.1364/AO.561465","url":null,"abstract":"<p><p>Optical polarization imaging technology provides multi-dimensional light field information, encompassing spatial details and polarization data, which can be exploited for image semantic segmentation for target scene analysis. Most recent works focus on the development of neural networks with separate simple preprocessing steps to deal with the raw polarization images, which limit the accuracy of semantic segmentation. This paper proposes a novel, to the best of our knowledge, method, dubbed cascade deep polarization network (CDPN), to improve the performance of semantic segmentation by integrating preprocessing modules directly into the end-to-end deep learning work. The raw input data include the angle of linear polarization, degree of linear polarization, and a set of Stokes parameters. The multi-dimensional feature maps are extracted from the raw data through the image denoising, fusion, and enhancement modules, which are then concatenated with a backbone network to obtain the segmentation results. By collaboratively training the preprocessing modules and backbone network with self-supervised loss functions, we strive to find out the optimal segmentation solution. Experimental results show that the proposed method can effectively improve the segmentation accuracy, while maintaining fast computation speed.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"8139-8150"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115949","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}

{"title":"Double-patterned waveguide resonators with conventional UV contact lithography.","authors":"Pei-Hsun Wang, Hung-Yu Chen, Yi Chang, Hsin-An Chen, Jia-Hao Cao, Yi-Xian Zhong, Chi-Ruei Huang","doi":"10.1364/AO.569558","DOIUrl":"https://doi.org/10.1364/AO.569558","url":null,"abstract":"<p><p>We propose a method for fabricating integrated microresonators using conventional ultraviolet contact lithography. By a double-patterning scheme, the bus- and resonator-waveguide can be lithography-patterned individually with a single photoresist spinning and etching process. A sub-µm gap is achieved between the bus- and resonator-waveguides, which exceeds the resolution limitation between patterns of the conventional contact-lithography process. The quality (Q) factor of waveguide resonators can be up to ≈10⁴, while the maximum measured extinction ratio of the resonator is larger than 20 dB. This double-patterning method offers easy fabrication, low cost, and sub-µm pitches for silicon photonics.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"7885-7892"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115952","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}

{"title":"Design, simulation, and experimental validation of a segmented beam-shaping integrator mirror.","authors":"Lei Feng, Jingxing Liao, Jingna Yang","doi":"10.1364/AO.569901","DOIUrl":"https://doi.org/10.1364/AO.569901","url":null,"abstract":"<p><p>Achieving uniform intensity distribution is essential for various laser applications such as material processing. This paper presents the design, simulation, and experimental validation of a segmented beam-shaping integrator mirror aimed at transforming an incident laser beam into a uniform line-shaped spot. The mirror surface is composed of multiple connected parabolic segments. A geometric optics computational method, implemented using Python code, was developed to determine the unique parameters and boundaries for each segment, based on input specifications including the working distance (<i>f</i>), the input aperture size (<i>D</i>), the target spot size (<i>d</i>), and the number of segments (<i>s</i>). For a design case with <i>D</i>=49.5<i>m</i><i>m</i>, <i>f</i>=350<i>m</i><i>m</i>, <i>d</i>=20<i>m</i><i>m</i>, and <i>s</i>=7, the segment parameters were calculated. The calculated design was modeled in SolidWorks, and its performance was simulated using Zemax ray tracing, predicting a shaped spot closely matching the 20 mm target size in the segmented direction and an expected size (approx. 1.4 mm) in the orthogonal direction. Experimental validation was conducted using a 4 kW fiber laser equipped with a fiber core diameter of 400 µm and a numerical aperture of 0.15, along with a collimating lens with a 100 mm focal length. The measured spot size at the target plane was 20.39<i>m</i><i>m</i>×1.41<i>m</i><i>m</i> (1/<i>e</i>² width), showing excellent agreement with both the design specification and the simulation results. This work successfully demonstrates the effectiveness of the integrator mirror design method and fabrication process for creating high-performance beam-shaping integrator optics for high-power laser systems.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"7893-7898"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115962","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}

{"title":"Investigation of linearity and interference effects in silicon photodiodes coupled to an integrating sphere for laser radiometry working standards.","authors":"Kanghee Lee, Seongchong Park, Dong-Hoon Lee","doi":"10.1364/AO.572858","DOIUrl":"https://doi.org/10.1364/AO.572858","url":null,"abstract":"<p><p>In laser radiometry, it is essential to evaluate the linearity of the detector and understand how interference effects influence power measurements, as laser light typically has high power and coherence. In this paper, we investigate the linearity and interference effects of widely used silicon photodiodes under the condition that they are coupled to an integrating sphere. For the linearity study, we employed a flux-addition method at 532 nm and found that one photodiode exhibited sufficient linearity, while the other showed supralinearity. This difference was attributed to whether the photodiode was irradiated with light outside its photoactive region. To further explore this, we examined the linearity by scanning the position of the laser irradiation on the photodiodes. In the interference study, we used a narrowband distributed Bragg reflector laser and measured the spectral responsivity by varying the laser wavelength. Due to the cover window, the spectral responsivity of photodiodes can rapidly vary as the wavelength changes under direct laser irradiation, with variations reaching up to tens of percent. However, when the spatial coherence of laser light is sufficiently suppressed by the integrating sphere, these rapid variations decrease to around 0.01% of the smoothly varying fitted values, which is negligible in typical laser power measurements.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"8037-8045"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145116047","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}

{"title":"Blind deblurring of retinal OCT images using an adaptive graph total variation.","authors":"Jiamin Wang, Shujun Men, Yang Tao, Yanke Li, Lei Zhang, Li Huo","doi":"10.1364/AO.571832","DOIUrl":"https://doi.org/10.1364/AO.571832","url":null,"abstract":"<p><p>We propose a blind deblurring method for retinal optical coherence tomography (OCT) images degraded by depth-dependent spatially variant blur. Our approach leverages an adaptive graph total variation (AGTV) prior, which dynamically adjusts regularization weights using local gradient statistics from the input image. AGTV autonomously enhances smoothing in severely blurred deep regions while preserving fine structures in shallow layers. Validated on microsphere images, en-face images, and B-scans, AGTV outperforms state-of-the-art methods in PSNR/SSIM metrics and significantly improves retinal layer segmentation accuracy-particularly for deep boundaries. This single-image framework requires no predefined PSF models or hardware modifications, offering a potential solution for clinical OCT enhancement.</p>","PeriodicalId":101299,"journal":{"name":"Applied optics","volume":"64 27","pages":"7921-7931"},"PeriodicalIF":0.0,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145115981","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}