Pub Date : 2026-04-01Epub Date: 2025-12-31DOI: 10.1016/j.optlaseng.2025.109588
Maria Cywińska, Wiktor Forjasz, Emilia Wdowiak, Michał Józwik, Adam Styk, Krzysztof Patorski, Maciej Trusiak
Full-field vibration profilometry is essential for dynamic characterizing microelectromechanical systems (MEMS/MOEMS). Time-averaged interferometry (TAI) encodes spatial information about MEMS/MOEMS vibration amplitude in the interferogram’s amplitude modulation using Bessel function (besselogram). Classical approaches for interferogram analysis are specialized for cosine function fringe patterns and therefore introduce reconstruction errors for besselogram decoding. This paper presents the DeepBessel: a deep learning-based approach for single-shot TAI interferogram analysis. A convolutional neural network (CNN) was trained using synthetic data, where the input consisted of besselograms, and the output corresponded to the underlying vibration amplitude distribution. Numerical validation and experimental testing demonstrated that DeepBessel significantly reduces reconstruction errors compared to the state-of-the-art approaches, e.g., Hilbert Spiral Transform (HST) method. The proposed network effectively mitigates errors caused by the mismatch between the Bessel and cosine functions. The results indicate that deep learning can improve the accuracy of full-field vibration measurements, offering new possibilities for optical metrology in MEMS/MOEMS applications.
{"title":"DeepBessel: deep learning-based full-field vibration profilometry using single-shot time-averaged interference microscopy","authors":"Maria Cywińska, Wiktor Forjasz, Emilia Wdowiak, Michał Józwik, Adam Styk, Krzysztof Patorski, Maciej Trusiak","doi":"10.1016/j.optlaseng.2025.109588","DOIUrl":"10.1016/j.optlaseng.2025.109588","url":null,"abstract":"<div><div>Full-field vibration profilometry is essential for dynamic characterizing microelectromechanical systems (MEMS/MOEMS). Time-averaged interferometry (TAI) encodes spatial information about MEMS/MOEMS vibration amplitude in the interferogram’s amplitude modulation using Bessel function (besselogram). Classical approaches for interferogram analysis are specialized for cosine function fringe patterns and therefore introduce reconstruction errors for besselogram decoding. This paper presents the DeepBessel: a deep learning-based approach for single-shot TAI interferogram analysis. A convolutional neural network (CNN) was trained using synthetic data, where the input consisted of besselograms, and the output corresponded to the underlying vibration amplitude distribution. Numerical validation and experimental testing demonstrated that DeepBessel significantly reduces reconstruction errors compared to the state-of-the-art approaches, e.g., Hilbert Spiral Transform (HST) method. The proposed network effectively mitigates errors caused by the mismatch between the Bessel and cosine functions. The results indicate that deep learning can improve the accuracy of full-field vibration measurements, offering new possibilities for optical metrology in MEMS/MOEMS applications.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109588"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885328","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}
Pub Date : 2026-04-01Epub Date: 2025-12-19DOI: 10.1016/j.optlaseng.2025.109561
Wei Qiao, Hongyi Lin, Dong Sun, Juqiang Lin
Fluorescence microscopy is inevitably plagued by out-of-focus background interference. However, conventional optical sectioning techniques often force a trade-off among imaging throughput, and background suppression capability, which compromises imaging performance—particularly in live-cell or large-volume three-dimensional (3D) imaging applications. Herein, we present a virtual illumination modulation-based HiLo method (v-HiLo) that computationally generates structured illumination, achieving single-exposure optical sectioning. Spoke-like sample simulation experiments and imaging of pollen particles have verified v-HiLo's capability to suppress out-of-focus background. Comparative experiments on biological samples using wide-field HiLo, deconvolution, and confocal imaging further confirm the superior optical sectioning performance of v-HiLo. Moreover, the combination of line-confocal microscopy and v-HiLo in mouse brain tissue imaging further verified that v-HiLo's virtual modulation approach can synergize with other optical sectioning techniques to enhance background suppression performance. v-HiLo leverages the advantages of virtual illumination modulation to achieve single- exposure optical sectioning while maintaining wide-field imaging's throughput. This breakthrough overcomes the fundamental trade-off among imaging speed, and background suppression in conventional optical sectioning techniques, providing an alternative avenues for large-scale 3D imaging and live-cell time-series observations.
{"title":"Single-exposure HiLo based on virtual illumination modulation","authors":"Wei Qiao, Hongyi Lin, Dong Sun, Juqiang Lin","doi":"10.1016/j.optlaseng.2025.109561","DOIUrl":"10.1016/j.optlaseng.2025.109561","url":null,"abstract":"<div><div>Fluorescence microscopy is inevitably plagued by out-of-focus background interference. However, conventional optical sectioning techniques often force a trade-off among imaging throughput, and background suppression capability, which compromises imaging performance—particularly in live-cell or large-volume three-dimensional (3D) imaging applications. Herein, we present a virtual illumination modulation-based HiLo method (v-HiLo) that computationally generates structured illumination, achieving single-exposure optical sectioning. Spoke-like sample simulation experiments and imaging of pollen particles have verified v-HiLo's capability to suppress out-of-focus background. Comparative experiments on biological samples using wide-field HiLo, deconvolution, and confocal imaging further confirm the superior optical sectioning performance of v-HiLo. Moreover, the combination of line-confocal microscopy and v-HiLo in mouse brain tissue imaging further verified that v-HiLo's virtual modulation approach can synergize with other optical sectioning techniques to enhance background suppression performance. v-HiLo leverages the advantages of virtual illumination modulation to achieve single- exposure optical sectioning while maintaining wide-field imaging's throughput. This breakthrough overcomes the fundamental trade-off among imaging speed, and background suppression in conventional optical sectioning techniques, providing an alternative avenues for large-scale 3D imaging and live-cell time-series observations.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109561"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799708","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}
Pub Date : 2026-04-01Epub Date: 2025-12-24DOI: 10.1016/j.optlaseng.2025.109564
Peixin Qu , Lulu Meng , Guohou Li , Jianping Wang , Wenyi Zhao , Zheng Liang , Weidong Zhang
Accurately evaluating underwater image quality is essential in marine engineering. Light attenuation and scattering in water often result in various visual distortions, including color loss, reduced contrast, and diminished visibility. In practical applications, these distortions may have a detrimental effect on the accurate evaluation of underwater images. To address the issue, we propose a method called Multidimensional Perceptual Image Quality Evaluation (MDP-IQE), designed to accurately and efficiently evaluate the underwater image quality. This method evaluates image quality across six key dimensions: color, contrast, visibility, geometry, noise, and water quality. The Gaussian Process Regression (GPR) model is trained to relate the extracted characterizations to the subjective quality scores of the underwater images. The quality-aware characterization vectors are then extracted for each test image and input into the trained model for quality prediction. Extensive testing on two datasets, which also show great compatibility with human subjective visual perception, demonstrates the superiority of our suggested MDP-IQE method.
{"title":"Underwater image quality evaluation via multidimensional perceptual characterization","authors":"Peixin Qu , Lulu Meng , Guohou Li , Jianping Wang , Wenyi Zhao , Zheng Liang , Weidong Zhang","doi":"10.1016/j.optlaseng.2025.109564","DOIUrl":"10.1016/j.optlaseng.2025.109564","url":null,"abstract":"<div><div>Accurately evaluating underwater image quality is essential in marine engineering. Light attenuation and scattering in water often result in various visual distortions, including color loss, reduced contrast, and diminished visibility. In practical applications, these distortions may have a detrimental effect on the accurate evaluation of underwater images. To address the issue, we propose a method called Multidimensional Perceptual Image Quality Evaluation (MDP-IQE), designed to accurately and efficiently evaluate the underwater image quality. This method evaluates image quality across six key dimensions: color, contrast, visibility, geometry, noise, and water quality. The Gaussian Process Regression (GPR) model is trained to relate the extracted characterizations to the subjective quality scores of the underwater images. The quality-aware characterization vectors are then extracted for each test image and input into the trained model for quality prediction. Extensive testing on two datasets, which also show great compatibility with human subjective visual perception, demonstrates the superiority of our suggested MDP-IQE method.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109564"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841611","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}
Pub Date : 2026-04-01Epub Date: 2025-12-24DOI: 10.1016/j.optlaseng.2025.109543
Xiangfeng Xie , Ping Xu , Ji Xu , Wenjie Zhang , Yian Liu , Haifeng Zheng
Hyperspectral images (HSIs) captures more comprehensive spectral information than traditional RGB imaging, offering significant potential across various applications. Conventional methods, such as point, line, and wavelength scanning, are capable of generating hyperspectral images, but are often time-consuming and costly. Snapshot imaging systems, like the Coded Aperture Snapshot Spectral Imaging (CASSI), snap three-dimensional hyperspectral data into two-dimensional measuremen, enabling faster acquisition, reduced costs, and enhanced miniaturization. Despite these advantages, CASSI-based systems continue to face significant challenges related to signal reconstruction algorithms, which restrict their commercial deployment. Recent advances in deep learning, particularly Convolutional Neural Network (CNN),have introduced innovative solutions for reconstructing hyperspectral images from 2D data. However, these methods typically demand substantial computational resources, making their implementation challenging for edge devices such as smartphones and drones. In this paper, we propose a lightweight multi-scale feature extraction and mask-gated convolutional network for hyperspectral image reconstruction. The network leverages lightweight design strategies for efficiency, incorporating channel dimension reduction and compact convolutional structures like 1×1 and depthwise separable convolutions. It further enhances reconstruction accuracy with a Channel Attention Module (CAM) that adaptively reweights features while reducing parameters. Additionally, the network integrates multi-scale feature extraction and mask-gated convolutional layers, enabling high-quality reconstruction with minimal computational cost.Experimental results demonstrate that the proposed approach not only reduces computational complexity and parameter count but also achieve high reconstruction performance compared to existing methods.
{"title":"Multi-scale feature extraction mask gated network for hyperspectral image reconstruction","authors":"Xiangfeng Xie , Ping Xu , Ji Xu , Wenjie Zhang , Yian Liu , Haifeng Zheng","doi":"10.1016/j.optlaseng.2025.109543","DOIUrl":"10.1016/j.optlaseng.2025.109543","url":null,"abstract":"<div><div>Hyperspectral images (HSIs) captures more comprehensive spectral information than traditional RGB imaging, offering significant potential across various applications. Conventional methods, such as point, line, and wavelength scanning, are capable of generating hyperspectral images, but are often time-consuming and costly. Snapshot imaging systems, like the Coded Aperture Snapshot Spectral Imaging (CASSI), snap three-dimensional hyperspectral data into two-dimensional measuremen, enabling faster acquisition, reduced costs, and enhanced miniaturization. Despite these advantages, CASSI-based systems continue to face significant challenges related to signal reconstruction algorithms, which restrict their commercial deployment. Recent advances in deep learning, particularly Convolutional Neural Network (CNN),have introduced innovative solutions for reconstructing hyperspectral images from 2D data. However, these methods typically demand substantial computational resources, making their implementation challenging for edge devices such as smartphones and drones. In this paper, we propose a lightweight multi-scale feature extraction and mask-gated convolutional network for hyperspectral image reconstruction. The network leverages lightweight design strategies for efficiency, incorporating channel dimension reduction and compact convolutional structures like 1×1 and depthwise separable convolutions. It further enhances reconstruction accuracy with a Channel Attention Module (CAM) that adaptively reweights features while reducing parameters. Additionally, the network integrates multi-scale feature extraction and mask-gated convolutional layers, enabling high-quality reconstruction with minimal computational cost.Experimental results demonstrate that the proposed approach not only reduces computational complexity and parameter count but also achieve high reconstruction performance compared to existing methods.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109543"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841609","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}
Pub Date : 2026-04-01Epub Date: 2025-12-24DOI: 10.1016/j.optlaseng.2025.109569
Fengrui Li , Zhigang Han , Jiarui Xu , Rihong Zhu
To mitigate vibration-induced phase errors in the demodulated wavefront of time-domain phase-shifting interferometry (PSI) systems, we present a synchronous calibration-acquisition method that precisely records sequential phase-shifting interferograms triggered by the phase-shifting features extracted from near-focal light signals. By integrating an electronic data processing module into the Fizeau interferometer, a closed-loop control system is established to dynamically track the peak-valley values of near-focal light intensity and generate real-time synchronization signals to the interferometer camera, enabling online phase-shift calibration and millisecond-level interferogram acquisition. This method can achieve non-isochronous sampling of four interferograms within 61 ms. Experimental results demonstrate that the method effectively suppresses ripple artifacts in demodulated wavefronts and reduces the incidence of inverted wavefronts, which can improve the operational stability of time-domain PSI systems in non-steady-state environments.
{"title":"Accurate and synchronous calibration-acquisition of phase-shifting interferograms under vibration with near-focal feature triggering","authors":"Fengrui Li , Zhigang Han , Jiarui Xu , Rihong Zhu","doi":"10.1016/j.optlaseng.2025.109569","DOIUrl":"10.1016/j.optlaseng.2025.109569","url":null,"abstract":"<div><div>To mitigate vibration-induced phase errors in the demodulated wavefront of time-domain phase-shifting interferometry (PSI) systems, we present a synchronous calibration-acquisition method that precisely records sequential phase-shifting interferograms triggered by the phase-shifting features extracted from near-focal light signals. By integrating an electronic data processing module into the Fizeau interferometer, a closed-loop control system is established to dynamically track the peak-valley values of near-focal light intensity and generate real-time synchronization signals to the interferometer camera, enabling online phase-shift calibration and millisecond-level interferogram acquisition. This method can achieve non-isochronous sampling of four interferograms within 61 ms. Experimental results demonstrate that the method effectively suppresses ripple artifacts in demodulated wavefronts and reduces the incidence of inverted wavefronts, which can improve the operational stability of time-domain PSI systems in non-steady-state environments.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109569"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842189","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}
Pub Date : 2026-04-01Epub Date: 2025-12-30DOI: 10.1016/j.optlaseng.2025.109580
Shuo Li , Yu Long , Lirong Zhong , Yajun Zhang , Mingfeng Liu , Yihu Zhang , Qi Gao , Xiahui Tang , Yu Xiao , Yingxiong Qin
Two-dimensional customized lasers obtained by conventional integrating mirrors are widely employed in industrial applications such as hardening, cladding, and surface heating, because of their high energy output efficiency and large radiation area. However, the existing two-dimensional customized lasers exhibit limited spot size along the length direction and an energy distribution confinement of the Gaussian mode along the width direction. In this work, we propose a novel generatrix design method, which is composed of alternating convex and concave high-order curve segments, to enhance energy uniformity and spot size along the length direction. Besides, a translation scheme applicable to all generatrixes is proposed to adjust the energy distribution along the width direction. Additionally, improved surface smoothness enhances manufacturability, allowing higher input power tolerance with minimal output loss. Here, we presented a 100.40-mm-long stripe-shaped laser, as well as a 21.17-mm-long dual-stripe-shaped laser with a peak interval of 3.98 mm. The energy distribution simulation results demonstrate the effectiveness of the novel beam shaping method and highlights its strong potential for high-power laser processing and other advanced laser applications.
{"title":"A novel method of designing integrating mirrors for two-dimensional customized lasers in surface hardening process","authors":"Shuo Li , Yu Long , Lirong Zhong , Yajun Zhang , Mingfeng Liu , Yihu Zhang , Qi Gao , Xiahui Tang , Yu Xiao , Yingxiong Qin","doi":"10.1016/j.optlaseng.2025.109580","DOIUrl":"10.1016/j.optlaseng.2025.109580","url":null,"abstract":"<div><div>Two-dimensional customized lasers obtained by conventional integrating mirrors are widely employed in industrial applications such as hardening, cladding, and surface heating, because of their high energy output efficiency and large radiation area. However, the existing two-dimensional customized lasers exhibit limited spot size along the length direction and an energy distribution confinement of the Gaussian mode along the width direction. In this work, we propose a novel generatrix design method, which is composed of alternating convex and concave high-order curve segments, to enhance energy uniformity and spot size along the length direction. Besides, a translation scheme applicable to all generatrixes is proposed to adjust the energy distribution along the width direction. Additionally, improved surface smoothness enhances manufacturability, allowing higher input power tolerance with minimal output loss. Here, we presented a 100.40-mm-long stripe-shaped laser, as well as a 21.17-mm-long dual-stripe-shaped laser with a peak interval of 3.98 mm. The energy distribution simulation results demonstrate the effectiveness of the novel beam shaping method and highlights its strong potential for high-power laser processing and other advanced laser applications.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109580"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885325","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}
Pub Date : 2026-04-01Epub Date: 2025-12-19DOI: 10.1016/j.optlaseng.2025.109557
Donghui Zhang , Tianxi Zhai , Cheng Zhang , Yilan Chen , Jian Cui , Xue Yan
This study tackled the challenge of high-sensitivity, optical measurement of subtle disturbances in underwater flow fields within weakly scattering media. A novel flow visualization approach based on schlieren differential interference imaging contrast was proposed. By leveraging polarization and birefringence modulation, the system amplified refractive index gradients between adjacent optical paths, markedly enhancing sensitivity to minor density perturbations and improving imaging contrast in low-scattering environments.In the experiments, by adjusting the object distance, it was shown that when the distance reached 5 cm, the double-image phenomenon disappeared and the rate of intensity variation increased significantly, enabling high-resolution reconstruction of flow-field details. Within the rotational speed range of 500–800 rpm, the flow density range broadened from 1015 to 1020 kg/m³ to 990–1020 kg/m³. The lowest density zone corresponded to the vortex core at high speed, highlighting the system’s responsiveness to velocity-induced density fluctuations. Phase maps revealed enhanced central brightness and spatial continuity. Combined with directional gradient analysis, the method successfully resolved fine flow features and density stratification at low speeds, while maintaining a high signal-to-noise ratio and fringe stability under rapid flow conditions. Furthermore, optical flow analysis was applied to multi-frame imaging data for quantitative validation. The reconstructed velocity distribution agreed closely with the schlieren differential interference imaging results, achieving an overall consistency of 96.88 %, further demonstrating the feasibility and reliability of this method for high-sensitivity, non-invasive flow visualization in weakly scattering underwater media. This work elucidated the physical response mechanisms of schlieren differential interference imaging in weakly scattering media and provided theoretical and technical support for high-precision flow measurements in complex underwater environments.
{"title":"Quantitative sensing of weak scattering medium flow field based on optical schlieren differential interferometry","authors":"Donghui Zhang , Tianxi Zhai , Cheng Zhang , Yilan Chen , Jian Cui , Xue Yan","doi":"10.1016/j.optlaseng.2025.109557","DOIUrl":"10.1016/j.optlaseng.2025.109557","url":null,"abstract":"<div><div>This study tackled the challenge of high-sensitivity, optical measurement of subtle disturbances in underwater flow fields within weakly scattering media. A novel flow visualization approach based on schlieren differential interference imaging contrast was proposed. By leveraging polarization and birefringence modulation, the system amplified refractive index gradients between adjacent optical paths, markedly enhancing sensitivity to minor density perturbations and improving imaging contrast in low-scattering environments.In the experiments, by adjusting the object distance, it was shown that when the distance reached 5 cm, the double-image phenomenon disappeared and the rate of intensity variation increased significantly, enabling high-resolution reconstruction of flow-field details. Within the rotational speed range of 500–800 rpm, the flow density range broadened from 1015 to 1020 kg/m³ to 990–1020 kg/m³. The lowest density zone corresponded to the vortex core at high speed, highlighting the system’s responsiveness to velocity-induced density fluctuations. Phase maps revealed enhanced central brightness and spatial continuity. Combined with directional gradient analysis, the method successfully resolved fine flow features and density stratification at low speeds, while maintaining a high signal-to-noise ratio and fringe stability under rapid flow conditions. Furthermore, optical flow analysis was applied to multi-frame imaging data for quantitative validation. The reconstructed velocity distribution agreed closely with the schlieren differential interference imaging results, achieving an overall consistency of 96.88 %, further demonstrating the feasibility and reliability of this method for high-sensitivity, non-invasive flow visualization in weakly scattering underwater media. This work elucidated the physical response mechanisms of schlieren differential interference imaging in weakly scattering media and provided theoretical and technical support for high-precision flow measurements in complex underwater environments.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109557"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799706","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}
Pub Date : 2026-04-01Epub Date: 2025-12-20DOI: 10.1016/j.optlaseng.2025.109562
Franzette Paz-Buclatin , Leopoldo Luis Martin , Alejandro González-Orive , Urma González-Tombolato , Kei Kamada , Akira Yoshikawa , Airán Ródenas Seguí
We report the first successful fabrication of monolithic all Yttrium Aluminum Garnet (YAG) crystalline microdisks directly in the bulk of a crystal, through a greatly simplified two-step process of three-dimensional femtosecond laser writing followed by chemical wet-etching, as compared to current multi-step approaches. The fabricated and optically characterized microdisk is 16.9 μm in diameter and 0.8 μm in thickness. We also present the first systematic study of surface tension reshaping in YAG by means of thermal annealing, identifying an optimal annealing temperature of 1475 °C for 5 h for smoothening surface irregularities. Optical characterization using tapered fiber loop evanescent coupling revealed a more than twofold improvement in the intrinsic quality factor of the Whispering Gallery Mode resonances, increasing from 3.6 × 10³ to 9.5 × 10³ after annealing. Furthermore, the YAG microdisks demonstrated outstanding thermal robustness, showing no observable morphological changes up to 1180 °C. This work establishes a robust and straightforward platform for fabricating monolithic inside-crystal YAG microresonators, enabling their application on chip-scale solid-state lasing and extreme environment sensing.
{"title":"Fabrication of a monolithic all-YAG crystalline microresonator through femtosecond laser nanolithography and thermal annealing","authors":"Franzette Paz-Buclatin , Leopoldo Luis Martin , Alejandro González-Orive , Urma González-Tombolato , Kei Kamada , Akira Yoshikawa , Airán Ródenas Seguí","doi":"10.1016/j.optlaseng.2025.109562","DOIUrl":"10.1016/j.optlaseng.2025.109562","url":null,"abstract":"<div><div>We report the first successful fabrication of monolithic all Yttrium Aluminum Garnet (YAG) crystalline microdisks directly in the bulk of a crystal, through a greatly simplified two-step process of three-dimensional femtosecond laser writing followed by chemical wet-etching, as compared to current multi-step approaches. The fabricated and optically characterized microdisk is 16.9 μm in diameter and 0.8 μm in thickness. We also present the first systematic study of surface tension reshaping in YAG by means of thermal annealing, identifying an optimal annealing temperature of 1475 °C for 5 h for smoothening surface irregularities. Optical characterization using tapered fiber loop evanescent coupling revealed a more than twofold improvement in the intrinsic quality factor of the Whispering Gallery Mode resonances, increasing from 3.6 × 10³ to 9.5 × 10³ after annealing. Furthermore, the YAG microdisks demonstrated outstanding thermal robustness, showing no observable morphological changes up to 1180 °C. This work establishes a robust and straightforward platform for fabricating monolithic inside-crystal YAG microresonators, enabling their application on chip-scale solid-state lasing and extreme environment sensing.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109562"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145799704","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}
Pub Date : 2026-04-01Epub Date: 2025-12-27DOI: 10.1016/j.optlaseng.2025.109579
Fang Wang , Yuchang Wen , Guoqing Shangguan , Shuangshuang Han , Xinyi Zhao , Yanzhong Yuan , Hualei Shen , Yufang Liu
We design a fiber-optic stress system based on strong optical feedback from a Fabry–Perot laser diode (FP-LD). It monitors stress changes induced by tilting of high-voltage transmission towers. The system comprises an external resonant cavity formed between the rear facet of the FP-LD and the end face of a single-mode fiber (SMF). The effective optical range length of the resonant cavity varies, which leads to a shift in the beat-frequency signal (BFS) of the multiple longitudinal modes. In the 0–80 N applied stress loading experiments of the sensing fiber, the stress variation is linearly related to the frequency shift of the BFS. The system sensitivity increased with increasing sensing resonator length. Specifically, for resonator lengths of 3.0 m, 5.1 m and 7.2 m, the measured stress sensitivities were −6.70 kHz·N⁻¹, −9.95 kHz·N⁻¹ and −13.67 kHz·N⁻¹, respectively. Applying a multilayer perceptron (MLP) neural network reduced the error between the stress values predicted from the frequency-shift monitoring software and the true stress measurements. This method improves the detection accuracy of the system and its MLP model has an accuracy of 96.88% in the test set.
{"title":"FP-LD strong feedback fiber-optic stress system for high-voltage transmission towers","authors":"Fang Wang , Yuchang Wen , Guoqing Shangguan , Shuangshuang Han , Xinyi Zhao , Yanzhong Yuan , Hualei Shen , Yufang Liu","doi":"10.1016/j.optlaseng.2025.109579","DOIUrl":"10.1016/j.optlaseng.2025.109579","url":null,"abstract":"<div><div>We design a fiber-optic stress system based on strong optical feedback from a Fabry–Perot laser diode (FP-LD). It monitors stress changes induced by tilting of high-voltage transmission towers. The system comprises an external resonant cavity formed between the rear facet of the FP-LD and the end face of a single-mode fiber (SMF). The effective optical range length of the resonant cavity varies, which leads to a shift in the beat-frequency signal (BFS) of the multiple longitudinal modes. In the 0–80 N applied stress loading experiments of the sensing fiber, the stress variation is linearly related to the frequency shift of the BFS. The system sensitivity increased with increasing sensing resonator length. Specifically, for resonator lengths of 3.0 m, 5.1 m and 7.2 m, the measured stress sensitivities were −6.70 kHz·N⁻¹, −9.95 kHz·N⁻¹ and −13.67 kHz·N⁻¹, respectively. Applying a multilayer perceptron (MLP) neural network reduced the error between the stress values predicted from the frequency-shift monitoring software and the true stress measurements. This method improves the detection accuracy of the system and its MLP model has an accuracy of 96.88% in the test set.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109579"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842190","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}
Pub Date : 2026-04-01Epub Date: 2025-12-24DOI: 10.1016/j.optlaseng.2025.109558
Jinye Miao , Yingjie Shi , Fuyao Cai , Yi Wei , Lingfeng Liu , Lianfa Bai , Enlai Guo , Jing Han
Non-line-of-sight (NLOS) imaging aims at reconstructing objects around corners and is promising for diverse applications. A fundamental problem is that the imaging resolution of NLOS methods based on time-of-flight (TOF) is constrained by the single-photon timing resolution (SPTR) of the hardware’s photon counting. In this paper, a super timing-resolution method named laser pulses multiplexing (LPM) is proposed to overcome the inherent photon counting limitations of the hardware. Specifically, based on the consistency of the laser pulse response, we can utilize the photon histogram of multiple laser pulse cycles and the fixed SPTR to form a sub-single-photon timing resolution (sub-SPTR) time-difference modulation matrix. In this way, without the necessity for additional optical components or multiple exposures, a high-SPTR transient images can be decoupled through time difference modulation. Through comprehensive evaluation of the experimental data, we demonstrate that LPM enhances SPTR by at least 1 order of magnitude, enabling transient image reconstruction with a 64-picosecond single-photon timing resolution—over 10 × higher than the hardware’s intrinsic 704-ps single-photon timing resolution. Furthermore, the proposed LPM exhibits robustness against Poisson noise induced by under-scanning conditions. Especially when the scanning points are reduced to about 5 % of full samples, the structural similarity index measure (SSIM) of the reconstructed object by LPM is 0.2 higher than that without LPM. In addition, experiments show that the proposed method is also applicable to non-confocal systems, which aids in the application of array detectors. The method reduces the reliance on high-SPTR detectors using pulse multiplexing modulation, which provides a reference for combining prior modulation to overcome hardware deficiencies.
{"title":"Super-resolution non-line-of-sight imaging with laser pulses multiplexing","authors":"Jinye Miao , Yingjie Shi , Fuyao Cai , Yi Wei , Lingfeng Liu , Lianfa Bai , Enlai Guo , Jing Han","doi":"10.1016/j.optlaseng.2025.109558","DOIUrl":"10.1016/j.optlaseng.2025.109558","url":null,"abstract":"<div><div>Non-line-of-sight (NLOS) imaging aims at reconstructing objects around corners and is promising for diverse applications. A fundamental problem is that the imaging resolution of NLOS methods based on time-of-flight (TOF) is constrained by the single-photon timing resolution (SPTR) of the hardware’s photon counting. In this paper, a super timing-resolution method named laser pulses multiplexing (LPM) is proposed to overcome the inherent photon counting limitations of the hardware. Specifically, based on the consistency of the laser pulse response, we can utilize the photon histogram of multiple laser pulse cycles and the fixed SPTR to form a sub-single-photon timing resolution (sub-SPTR) time-difference modulation matrix. In this way, without the necessity for additional optical components or multiple exposures, a high-SPTR transient images can be decoupled through time difference modulation. Through comprehensive evaluation of the experimental data, we demonstrate that LPM enhances SPTR by at least 1 order of magnitude, enabling transient image reconstruction with a 64-picosecond single-photon timing resolution—over 10 × higher than the hardware’s intrinsic 704-ps single-photon timing resolution. Furthermore, the proposed LPM exhibits robustness against Poisson noise induced by under-scanning conditions. Especially when the scanning points are reduced to about 5 % of full samples, the structural similarity index measure (SSIM) of the reconstructed object by LPM is 0.2 higher than that without LPM. In addition, experiments show that the proposed method is also applicable to non-confocal systems, which aids in the application of array detectors. The method reduces the reliance on high-SPTR detectors using pulse multiplexing modulation, which provides a reference for combining prior modulation to overcome hardware deficiencies.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"199 ","pages":"Article 109558"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841610","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号