Heyan Wang , Nuo Xu , Jianghai He , Dongzhen Wang , Zhengang Lu , Yilei Zhang , Jiubin Tan
{"title":"Enhancing optical transparency of photonic crystals for high-performance electromagnetic interference shielding","authors":"Heyan Wang , Nuo Xu , Jianghai He , Dongzhen Wang , Zhengang Lu , Yilei Zhang , Jiubin Tan","doi":"10.1016/j.optlaseng.2025.109293","DOIUrl":"10.1016/j.optlaseng.2025.109293","url":null,"abstract":"<div><div>In recent years, electromagnetic interference has caused serious threats to both electronic systems and human health. Transparent electromagnetic shielding technology has become a crucial research area for achieving shielding while ensuring optical transparency. This study investigated one-dimensional metal/dielectric photonic crystals on microwave shielding and light transmission. We first found that shielding capability depends primarily on total metal thickness in photonic crystals, rather than its distribution. Particularly, by subdividing the metal into multiple periods with a constant thickness, substantial enhancement in visible transmittance can be achieved while preserving equivalent shielding performance. Accordingly, a high-quality ultra-thin doped silver (8 nm) was employed to construct photonic crystals verifying the assumption. Experiments show that, at a silver film thickness of 24 nm, subdividing into three periods relatively increases the average transmittance by 70.1% (theoretically more than 100%) over the single-layer metal film. Meanwhile, the shielding effectiveness remains consistent for all configurations, with each measurement exceeding -32 dB. In addition, we have established the multi-beam interference-based model to analyze the transmission of microwaves and visible light in photonic crystals. The results are expected to guide refining the optical properties of metal shielding films and exploring the limits of light transmission achievable in experiments for photonic crystals.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109293"},"PeriodicalIF":3.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sara Fernandez-Nuñez , Jose Antonio Gomez-Pedrero , Francisco Jose Torcal-Milla , Luis Miguel Sanchez-Brea
{"title":"Chessboard-based achromatic binary Zone Plate","authors":"Sara Fernandez-Nuñez , Jose Antonio Gomez-Pedrero , Francisco Jose Torcal-Milla , Luis Miguel Sanchez-Brea","doi":"10.1016/j.optlaseng.2025.109303","DOIUrl":"10.1016/j.optlaseng.2025.109303","url":null,"abstract":"<div><div>We numerically and experimentally demonstrate the performance of a new kind of diffractive binary zone plate for chromatic aberration compensation: the chessboard-based zone plate. The proposed achromatic zone plate consists of two spatially multiplexed zone plates following the geometry given by a chessboard and improved with morphological filters and combination under the Nyquist frequency, to mitigate aliasing effects. The obtained results are compared with those given by a random pixel-based multiplexed zone plate, reported in the literature, showing similar optical behaviour. However, the chessboard-based zone plate presents a smoother appearance without the high-frequency irregularities of the random-based designs that could be more resistant to manufacturing errors. The proposed achromatic zone plate could result of interest in fields such as solar concentration, lithography, imaging systems, visual optics, and so on.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109303"},"PeriodicalIF":3.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aoming Zhang , Zimeng Jiang , Lang Cheng , Chenguang Ma , Weijie Hong , Yingjie Zhang
{"title":"Few-shot learning-based generalization detection for challenging part contour in laser powder bed fusion","authors":"Aoming Zhang , Zimeng Jiang , Lang Cheng , Chenguang Ma , Weijie Hong , Yingjie Zhang","doi":"10.1016/j.optlaseng.2025.109274","DOIUrl":"10.1016/j.optlaseng.2025.109274","url":null,"abstract":"<div><div>In additive manufacturing process, most existing data-driven methods are trained on high-quality samples with simple geometries from discontinuous layers. Such models, which have extremely poor generalization in challenging samples with small size, complex geometry, bad lighting and ambiguous boundary. This work proposes a Progressive Coarse-to-Fine Network (PCFNet) for fine contour detection of the parts with different geometries. Firstly, This paper provides a mixed part contour dataset comprising a large number of simple samples and a small number of challenging samples. Furthermore, the dilemma of data-driven methods for LPBF online detection is examined by decoupling the similarity between the high-level features of the representative sampled images. Finally, combined with the few-shot learning can improve PCFNet's fine detection level for simple samples and generalization performance for challenging ones. The quantitative and qualitative results on both public and our own datasets demonstrate that the proposed PCFNet exhibits superior detection and generalization performance, significantly outperforming twelve state-of-the-art detection methods. The methodology can detect the layer-wise contour of an orthotropic lattice with the diameter of <span><math><mn>0.25</mn><mi>m</mi><mi>m</mi></math></span> (≈3 pixels), achieving a statistical fidelity exceeding 84% (mIoU).</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109274"},"PeriodicalIF":3.7,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuanwei Xie, Xiaozheng Fan, Chenyoukang Lin, Zilong Xue, Bo Wang
{"title":"ILLVFusion: Infrared and low-light visible image fusion based on CNN and transformer","authors":"Yuanwei Xie, Xiaozheng Fan, Chenyoukang Lin, Zilong Xue, Bo Wang","doi":"10.1016/j.optlaseng.2025.109267","DOIUrl":"10.1016/j.optlaseng.2025.109267","url":null,"abstract":"<div><div>In the field of image fusion, particularly in nocturnal or low-illumination conditions, the effective integration of infrared and visible light images to enhance image quality remains a pressing issue. This study introduces an innovative image fusion framework named ILLVFusion, which comprises three critical networks: the Low-Light Image Enhancement Network (LLIEN), the Fusion Network (FN), and the Brightness Feedback Network (BFN). The LLIEN module is designed to boost the brightness of low-light visible light images and reduce noise interference, thereby generating images with balanced color and lower noise levels. The fusion network FN employs a dual-branch encoder structure based on Convolutional Neural Network (CNN) and Transformer, aiming to efficiently extract global and detailed features from the input images. The BFN module provides brightness feedback to optimize the output of the LLIEN module, resulting in images with reasonable brightness. Additionally, this study proposes a novel intensity loss function to ensure that the fused image retains detailed information from the original pixel intensity. Extensive experimental results demonstrate that ILLVFusion has achieved significant performance in the image fusion task.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109267"},"PeriodicalIF":3.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenzong Lai , Weijie Hao , Jinlong Xie , Junhu Cai , Huajian Jin , Yu Chen , Ziming Yao , Yun Ye , Sheng Xu , Qun Yan , Tailiang Guo , Enguo Chen
{"title":"Resolution enhancement of Micro-LED projection displays via high-frequency vibration","authors":"Wenzong Lai , Weijie Hao , Jinlong Xie , Junhu Cai , Huajian Jin , Yu Chen , Ziming Yao , Yun Ye , Sheng Xu , Qun Yan , Tailiang Guo , Enguo Chen","doi":"10.1016/j.optlaseng.2025.109271","DOIUrl":"10.1016/j.optlaseng.2025.109271","url":null,"abstract":"<div><div>Micro-LED, known for its high brightness, wide color gamut, long lifespan, and reliability, has attracted significant attention and holds great potential for self-emissive micro-projection and near-eye displays. However, current challenges in manufacturing and repair pose significant obstacles to improving the Micro-LED’s pixel density, thereby impacting further micro-display developments. To address this, this paper proposes a novel resolution-enhanced approach for Micro-LED projection display that integrates a high-frequency vibrating glass (HVG) between the Micro-LED display panel and the projection lens, achieving four times the image resolution without boosting the native resolution of the Micro-LED panel. Based on the principle of beam lateral displacement and time multiplexing, multiple spatially offset images of the Micro-LED panel is generated by controlling the HVG’s vibration angle and then superimposed by the projection lens. Experimental results confirm the spatial image shifting effect through precise control of the HVG’s vibration direction and angle, effectively doubling the number of horizontal and vertical pixels respectively. The display resolution of the Micro-LED projection is finally enhanced by four times—currently the highest in projection resolution enhancement techniques. This proposed system pushes the boundaries of self-emissive projection technology and offers a novel solution for ultra-high-resolution Micro-LED displays.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109271"},"PeriodicalIF":3.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinhao Shi , Jinge Guan , Yongqiu Zheng , Nan Li , Chenyang Xue
{"title":"Near-infrared tomographic thermometry for three-dimensional flame based on multi-level parallel defocusing","authors":"Jinhao Shi , Jinge Guan , Yongqiu Zheng , Nan Li , Chenyang Xue","doi":"10.1016/j.optlaseng.2025.109297","DOIUrl":"10.1016/j.optlaseng.2025.109297","url":null,"abstract":"<div><div>In this work, a near-infrared tomographic thermometry method based on the multi-level parallel defocusing is proposed, which can measure the three-dimensional temperature of combustion flame. By applying Fourier optics to establish the object-image mapping relationship, three-dimensional gray level model of the combustion flame is analyzed, and the combustion temperature is calculated by utilizing Planck's radiation law. The thermometer is designed with different imaging channels, each focused on different axial sections of flame. It consists of integrated beam splitter, synchronous control circuit, imagers and mechanical packaging. Firstly, the flame radiation is distributed to different output channels through an integrated splitting prism as the beam splitter. A field programmable gate array (FPGA) circuit is used to drive the imagers arranged at different channel ports for the acquisition of transient combustion flame information, and the mechanical structure is employed to fabricate the overall package. Secondly, the coaxial optical path of thermometer, the point spread function and the photoelectric mapping are calibrated for higher precision measurement. After the calibration, the effectiveness of tomography is verified by the four-layer acrylic plate with an axial 15 mm interval. The section information at different spatial positions along the axis direction can be separated. After screening the flame spectral information, the appropriate measurement band is selected. Finally, the temperature measurement experiment of the tail flame of the solid burner is carried out. The experimental results show that between the theoretical value and the measured value, the maximum measurement error is within 10 %.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109297"},"PeriodicalIF":3.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimentally calibrated weight-matrix-coupled GFP-SART algorithm for 3D particle field reconstruction through light field imaging","authors":"Manfu Chen, Jian Li, Biao Zhang, Chuanlong Xu","doi":"10.1016/j.optlaseng.2025.109294","DOIUrl":"10.1016/j.optlaseng.2025.109294","url":null,"abstract":"<div><div>Accurate three-dimensional (3D) flow field measurement through light field particle image velocimetry (LF-PIV) relies on the precise reconstruction of tracer particle positions and luminescent intensities. This accuracy depends heavily on the performance of the tomographic reconstruction algorithm and the fidelity of the associated weight matrix. This paper proposes a novel method—ECWM-GFP-SART—that enhances the reconstruction accuracy by integrating 3D Gaussian fitting positioning (GFP) into the simultaneous algebraic reconstruction technique (SART) algorithm to mitigate axial elongation of particles, and by constructing an experimentally calibrated weight matrix (ECWM) to correct deviations between theoretical and actual imaging models. The GFP method improves particle positioning by applying Gaussian fitting to the intensity distribution of elongated particles, effectively eliminating the elongation artifacts. Meanwhile, the ECWM is established by analyzing the ratio between the grayscale values of light field images obtained from the point light sources to their actual luminescent intensities, producing an accurate weight matrix consistent with experimental conditions. The effectiveness of the proposed ECWM-GFP-SART method is evaluated by reconstructing 3D particle fields with concentrations ranging from 0.20 to 0.80 particles per micro-lens (ppm), and compared against the traditional SART algorithm. Results demonstrate that ECWM-GFP-SART significantly improves the weight matrix accuracy and effectively eliminate the axial elongation of particles. Compared to the traditional SART, ECWM-GFP-SART increases the reconstruction quality coefficient from 0.10 to over 0.92 and accelerates the reconstruction speed by a factor of four.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109294"},"PeriodicalIF":3.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kangjian Li , Zuoqiang Han , Jiarui Yi , Shuohong Jia , Li Kuang , Xiaolang Qiu , Jing Zhang , Chuanchuan Li , Yulian Cao , Xin Wei , Haiyang Yu , Jianguo Liu , Suo Wang
{"title":"Systematic analysis of correlated self-heterodyne method for intrinsic linewidth measurement","authors":"Kangjian Li , Zuoqiang Han , Jiarui Yi , Shuohong Jia , Li Kuang , Xiaolang Qiu , Jing Zhang , Chuanchuan Li , Yulian Cao , Xin Wei , Haiyang Yu , Jianguo Liu , Suo Wang","doi":"10.1016/j.optlaseng.2025.109298","DOIUrl":"10.1016/j.optlaseng.2025.109298","url":null,"abstract":"<div><div>The correlated self-heterodyne method demonstrates significant advantages over conventional delayed self-heterodyne beating techniques for Hz-level intrinsic linewidth measurement. This innovative approach achieves superior performance through significantly shorter delay fiber lengths while maintaining exceptional versatility in measuring lasers at specialized wavelengths. In this work, we achieve intrinsic linewidth measurement deviations better than 2.5 % from sub-Hz to sub-kHz scales at a cost of $30k when compared to a $300k commercial linewidth analyzer. Furthermore, we systematically investigate and quantify the critical parameter boundaries, including the length of delay fiber and the sampling time of oscilloscope, governed by laser coherence properties. We also apply this method to specialized wavelength, such as 510 nm, which has a wide range of applications in quantum precision applications, and the intrinsic linewidth is 14.45 Hz. Our work establishes a robust framework for narrow-linewidth laser metrology, supporting advancements in precision optics and quantum technologies.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109298"},"PeriodicalIF":3.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shengchun Wang , Haowen Li , Lianye Liu , Ronghui Cai , Zhonghai Yin , Huijie Zhu
{"title":"TSFI-fusion: A dual-branch decoupled infrared and visible image fusion network based on transformer and spatial-frequency interaction","authors":"Shengchun Wang , Haowen Li , Lianye Liu , Ronghui Cai , Zhonghai Yin , Huijie Zhu","doi":"10.1016/j.optlaseng.2025.109287","DOIUrl":"10.1016/j.optlaseng.2025.109287","url":null,"abstract":"<div><div>Infrared and visible image fusion (IVIF) aims to generate high-quality images by combining detailed textures from visible images with the target-highlight capabilities of infrared images. However, many existing methods struggle to capture both shared and unique features of each modality. They often focus only on spatial domain fusion, such as pixel averaging, while overlooking valuable frequency domain information. This makes it hard to retain fine details. To overcome these limitations, we propose TSFI-Fusion, a dual-branch network that combines Transformer-based global understanding with spatial-frequency detail enhancement. The two branches include a Transformer-based semantic construction branch for capturing global features and a detail enhancement branch utilizing an invertible neural network (INN) and a frequency domain compensation module (FDCM) to integrate spatial and frequency information. We also design a dual-domain interaction module (DDIM) to improve feature correlation across domains and a collaborative information integration module (CIIM) to effectively merge features from both branches. Additionally, we introduce a focal frequency loss to guide the model in learning important frequency information. Experimental results demonstrate that TSFI-Fusion outperforms existing methods across multiple datasets and metrics on the IVIF task. In downstream applications such as object detection, it effectively enhances performance. Furthermore, extended experiments on the MIF task reveal the robust generalization ability of the proposed mechanism across diverse fusion scenarios. Our code will be available at <span><span>https://github.com/lihaowen0109/TSFI-Fusion</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109287"},"PeriodicalIF":3.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Digital holographic sound field imaging beyond Nyquist frequency","authors":"Nao Sakiyama , Naru Yoneda , Yasuhiro Awatsuji , Osamu Matoba","doi":"10.1016/j.optlaseng.2025.109288","DOIUrl":"10.1016/j.optlaseng.2025.109288","url":null,"abstract":"<div><div>This paper presents digital holographic sound field imaging method for sound fields containing frequencies above the Nyquist frequency. Digital holography is a non-invasive interference-based imaging technique that enables high-spatial-resolution visualization of sound fields using image sensors. However, according to Nyquist-Shannon sampling theorem, accurate frequency acquisition requires a frame rate at least twice the maximum frequency of the sound fields. This constraint limits the field of view due to readout bandwidth limitation of image sensors. To address this, we propose a technique that reconstructs high-frame-rate sound fields from lower-frame-rate recordings through computational reconstruction using the wavelength information of the sound-field images. Experimental results show that the proposed method achieves a twenty-fold improvement in temporal resolution and an eight-fold increase in the field of view compared to the conventional digital holographic method. This achieves sound field imaging even with low-frame-rate image sensors.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"195 ","pages":"Article 109288"},"PeriodicalIF":3.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}