Optics and Lasers in Engineering最新文献

{"title":"Pixel-wise calibration for a multi-focus microscopic 3D imaging system","authors":"Yuchen Yang,&nbsp;Song Zhang","doi":"10.1016/j.optlaseng.2025.109127","DOIUrl":"10.1016/j.optlaseng.2025.109127","url":null,"abstract":"<div><div>This paper presents a novel pixel-wise calibration method for a multi-focus microscopic structured light (MF-MSL) three-dimensional (3D) system with the camera being attached an electronically tunable lens (ETL). The method begins with a conventional stereo calibration performed at a selected focus. Next, a pixel-wise relationship between the continuous focus settings and corresponding phase values is established using a stationary white plane as the reference. By translating the white plane across the depth range defined by the ETL's continuous focus, a pixel-wise relationship between the phase difference (i.e., the deviation from the reference phase) and the 3D coordinates is derived. This process ultimately yields a direct mapping between the continuous focus values and 3D coordinates at each pixel. Since the proposed pixel-wise calibration method mitigates lens artifacts during focus variations, it greatly improved the calibration accuracy. Experimental results demonstrated that, comparing to the traditional stereo method, the proposed method reduced the root-mean-square error (rmse) by more than 50% for our 10× extended depth of field (DoF) system.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109127"},"PeriodicalIF":3.5,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261691","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":"Effects of heat transfer characteristics of atmospheric horizontal buoyant jets on optical aberrations in a laser system","authors":"Ji Hun Kim,&nbsp;Joohan Kim","doi":"10.1016/j.optlaseng.2025.109132","DOIUrl":"10.1016/j.optlaseng.2025.109132","url":null,"abstract":"<div><div>An effective thermal monitoring and management strategy is required to ensure stable performance of an optical system. Although forced convection cooling systems help to maintain the temperature within an appropriate range, such systems always exhibit temperature gradients and turbulence. The resulting thermal lensing effects degrade optical performance. An understanding of the convective heat transfer characteristics and thermal lensing effects is essential for optimizing optical system performance. This study analyzes the independent thermo-optical effects of convective heat transfer by a horizontal buoyant jet. The results showed that the buoyancy of the jet induced an increase in the core flow. Rays passing through the flow exhibited various aberrations including a negative Y-tilt, positive defocus, and negative vertical astigmatism. These effects intensified as the discharge temperature increased. Turbulent dissipation rate analysis revealed that the variability of these aberrations was attributable to fluctuations in the thermodynamic parameters of air. The variability increased at turbulent dissipation rates. Based on the theoretical background of thermo-optical phenomena in air, the effect of convective heat transfer on these aberrations was explored via numerical simulations and experimentally validated using a Shack–Hartmann wavefront sensor. These findings indicate that quantitative aberration-based analytical methods aid optical quality evaluation in terms of the thermal management of optical systems.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109132"},"PeriodicalIF":3.5,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144272427","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":"Underwater polarization image enhancement based on low-rank polarization tensor model","authors":"Yulin Wang,&nbsp;Yueming Ma,&nbsp;Yuehan Chen,&nbsp;Jianda Wang,&nbsp;Xianping Fu","doi":"10.1016/j.optlaseng.2025.109157","DOIUrl":"10.1016/j.optlaseng.2025.109157","url":null,"abstract":"<div><div>Polarization imaging techniques are widely used in underwater image enhancement due to their unique physical properties. Accurate estimation of the degree of polarization (DoP) of backscatter is crucial for the effectiveness of polarization-based underwater image enhancement methods. However, most existing methods often rely on the assumptions that target reflections are unpolarized and that the DoP of backscatter remains spatially constant. These can lead to substantial errors in the DoP of backscatter estimation, adversely affecting the quality of image recovery. To address these limitations, we propose a novel underwater polarization image enhancement method, called LRPT, based on the low-rank polarization tensor model. This method uniquely integrates the influence of target reflection polarization on imaging results. By expressing the DoP of polarized light as a linear combination of the DoP of backscatter and that of the target, LRPT allows for a more accurate estimation of the three-dimensional DoP of the backscatter matrix at the pixel level, rather than assuming a constant backscatter polarization value. Furthermore, to enhance the generalization ability of the method, we designed a dual orthogonal stretch correction module, which effectively resolves color distortion issues in color-polarized images while preserving the polarization relationships among orthogonally polarized images. Numerous experiments demonstrate that the LRPT method not only mitigates problems related to low contrast and color distortion in underwater images but also exhibits robust performance and strong generalization capabilities.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109157"},"PeriodicalIF":3.5,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261687","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":"Compact dual-wavelength common-path digital holographic microscope for dynamic topography reconstruction","authors":"Yuxuan Zhao ,&nbsp;Zhiming Lin ,&nbsp;Zhiwen Deng ,&nbsp;Qiwen Jin ,&nbsp;Yingchun Wu ,&nbsp;Chenghang Zheng ,&nbsp;Zhibin Wang ,&nbsp;Xuecheng Wu","doi":"10.1016/j.optlaseng.2025.109156","DOIUrl":"10.1016/j.optlaseng.2025.109156","url":null,"abstract":"<div><div>In this study, we present a compact dual-wavelength common-path digital holographic microscopy (DHM) system for high-precision morphological and dynamic measurements. The system ensures high-precision measurements with simpler optical path layout and calibration mode. The time stability of the system is firstly evaluated and compared with traditional dual-wavelength DHM setups, demonstrating significant improvement in noise suppression and measurement precision. Then, topographic measurements of a standard step sample with a height of 4 μm are carried out, showing an overall standard deviation of surface height of 47.83 nm, which is notably lower than that obtained with conventional systems. Finally, the system's dynamic imaging capability is demonstrated through real-time tracking of the movement of platymonas, confirming the system's excellent performance in dynamic monitoring. The proposed DHM system offers high stability, accuracy, and real-time capability, making it suitable for a wide range of applications in biological dynamic imaging and material science.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109156"},"PeriodicalIF":3.5,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261690","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":"Performance and analysis of pressure sensor with π-FBG on thick-walled cylinder for ultra-high oceanic pressure measurement","authors":"Qingquan Sun ,&nbsp;Muzi Zhang ,&nbsp;Shanshan Zhao ,&nbsp;Lanting Ji ,&nbsp;Juan Su ,&nbsp;Jie Xu ,&nbsp;Bo Yang ,&nbsp;Chi Wu","doi":"10.1016/j.optlaseng.2025.109147","DOIUrl":"10.1016/j.optlaseng.2025.109147","url":null,"abstract":"<div><div>Accurate pressure measurements in deep-sea environments require ultra-high-pressure sensors that maintain high precision across a wide range of temperatures and pressures. This paper presents the design and performance analysis of an ultra-high-pressure sensor based on a thick-walled cylindrical π-phase-shifted fiber Bragg grating (π-FBG). The sensor consists of a π-FBG element, a pressure conversion unit, and a robust encapsulation structure. It operates efficiently within a pressure range of 2 to 120 MPa, with a pressure sensitivity of 5.884 pm/MPa and a measurement accuracy of 0.033 % Full Scale (F.S.), offering both a wide dynamic range and high precision. A modified finite element model (FEM) is developed, incorporating the composite structure of the π-FBG and adhesive interface, to optimize sensor design and improve analytical accuracy. Simulation results confirm the critical influence of structural and bonding parameters on pressure response and successfully predict the wavelength shifts induced by external pressure. The model also reveals key insights into the stress-strain behavior, interfacial strain transfer, and pressure sensitivity. To evaluate temperature effects on pressure sensitivity, controlled experiments were conducted at 2°C, 5°C, 8°C and 20°C, simulating deep-sea temperature environments. The results indicate a linear relationship between pressure sensitivity and temperature. A calibration equation is proposed to compensate for the temperature-induced deviations, maintaining a relative error less than 0.033 % F.S. throughout the 2–20°C range. The sensor features a compact design, straightforward fabrication, and simple calibration procedure, making it suitable for applications in extreme environments, such as deep-sea exploration and downhole pressure measurements. This work advances the analytical framework for π-FBG-based ultra-high-pressure sensors and contributes new insights into the development of next-generation deep-sea measurement technologies.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109147"},"PeriodicalIF":3.5,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261689","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":"Color Image Encryption Using Spatial OAM Beam through a Multimode Fiber","authors":"Ruibo Lan,&nbsp;Hongbin Hu,&nbsp;Longjun Zheng,&nbsp;Yubin Zang,&nbsp;Zuxing Zhang","doi":"10.1016/j.optlaseng.2025.109146","DOIUrl":"10.1016/j.optlaseng.2025.109146","url":null,"abstract":"<div><div>This paper proposes an optical color image encryption scheme to resist unsupervised machine learning attacks. The encryption system first encodes the pixel information of the plaintext color image using an orbital angular momentum (OAM) hologram while carrying RGB color information using the spatial degrees of freedom of vortex beam. Then, the information-encoded OAM beam is transmitted through a physically perturbed multimode optical fiber to generate the speckles as the encrypted ciphertext. Finally, the pre-trained Asymmetric Decoupling Deep Learning-based (ADDL) model takes the output speckles as input and successfully retrieves the grayscale value together with its corresponding color channel for decryption purposes. The proposed scheme uses spatial degrees of freedom to carry color information and achieves de-synchronized high-security color image encryption transmission. The system not only reconstructs high-fidelity images but also resists unsupervised machine learning attacks, ensuring enhanced security. Our work provides a promising path for further research on optical color image transmission and encryption with ultra-high security and crack resistance.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109146"},"PeriodicalIF":3.5,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144254753","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":"Edge-filtering-based high-frequency parameter characterization for MG-Y lasers","authors":"Yu Cheng ,&nbsp;Wei Zhuang ,&nbsp;Hong Li ,&nbsp;Xu Zhang ,&nbsp;Lianqing Zhu","doi":"10.1016/j.optlaseng.2025.109120","DOIUrl":"10.1016/j.optlaseng.2025.109120","url":null,"abstract":"<div><div>The parameter characterization of Modulated Grating Y-branch (MG-Y) tunable lasers is essential for ensuring stable and precise wavelength output. To meet the high sampling rate demands during high-frequency laser tuning, this paper proposes an edge-filtering-based characterization method tailored for MG-Y lasers. The method employs a Tunable Fiber Filter(TFF) to perform edge filtering on the laser output. The filtered optical power is detected by a Photo-Diode(PD) and converted into a voltage signal, enabling a sampling rate significantly higher than that of conventional instruments such as spectrometers or wavelength meters. Utilizing the laser’s low-frequency tuning path, a Particle Swarm Optimization (PSO) algorithm is applied to iteratively determine the optimal control parameter sets for designated wavelength targets. This enables the characterization of MG-Y lasers under high-frequency tuning conditions and supports the generation of a current-to-wavelength Look-Up Table (LUT). Experimental results demonstrate that the constructed LUT contains 2001 wavelength points over a 40 nm tuning range, achieving a wavelength accuracy of ±5.8 pm with a standard deviation of 2.8 pm at a tuning frequency of 200.71 kHz, thereby meeting the performance requirements for subsequent Fiber Bragg Grating (FBG) demodulation applications.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109120"},"PeriodicalIF":3.5,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144261686","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":"Interferometric measurement of discontinuous surfaces based on morphology method","authors":"Shuai Wang ,&nbsp;Bosong Duan ,&nbsp;Bingfeng Ju ,&nbsp;Wule Zhu","doi":"10.1016/j.optlaseng.2025.109131","DOIUrl":"10.1016/j.optlaseng.2025.109131","url":null,"abstract":"<div><div>In measurement scenarios such as interferometry, reliable phase unwrapping plays an essential role in ensuring accurate performance. With the increasing demand for non-continuous surface measurements, the need for measurement of discontinuous surfaces is becoming increasingly important. However, for existing phase unwrapping algorithms, it remains quite challenging to unwrap discontinuous phases both accurately and efficiently. To conquer these challenges, we propose a new algorithm based on mathematical morphology and managed to unwrap discontinuous phase map. With adequate mask design, a discontinuous form measurement was successfully achieved with numerical deviation of 1/19λ in PV and 1/40λ (λ=632.8nm) in RMS compared to equipment-measured benchmark.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109131"},"PeriodicalIF":3.5,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144254754","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":"Fringe pattern denoising with a deep neural network","authors":"Jesús Villa ,&nbsp;Gamaliel Moreno ,&nbsp;Efrén González ,&nbsp;Daniel Alaniz ,&nbsp;Ismael de la Rosa ,&nbsp;Jorge Luis Flores ,&nbsp;Guillermo García-Torales","doi":"10.1016/j.optlaseng.2025.109134","DOIUrl":"10.1016/j.optlaseng.2025.109134","url":null,"abstract":"<div><div>Interferometric images (e.g., fringe and wrapped-phase patterns) are pivotal in optical metrology and industrial inspection, yet their accuracy is often compromised by noise from sensor imperfections, environmental fluctuations, and instrumental limitations. While many traditional denoising methods require case-specific parameter tuning or prior fringe orientation estimation, deep learning approaches face challenges in accessibility and implementation complexity.</div><div>We propose a Deep Neural Network Filter (DNNF), a novel denoising technique that combines the robustness of deep learning with the simplicity of convolution filters. Our method employs a custom-designed deep neural network (DNN) trained on a synthetic dataset encompassing diverse local fringe structures (orientation, frequency, curvature) and noise profiles (Gaussian phase noise). The DNNF operates as a parameter-free, plug-and-play solution, processing images analogously to a convolution filter without requiring manual adjustments or fringe orientation estimation.</div><div>Extensive experiments on synthetic and real interferometric images demonstrate the DNNF's competitive performance against some state-of-the-art methods. Key achievements include: good noise suppression while avoiding artifacts common in anisotropic filters. Balanced processing time without compromising accuracy. Consistent performance across varied fringe densities, orientations, and noise levels, validated in moiré interferometry, Michelson interferometry, and Electronic Speckle Pattern Interferometry (ESPI) applications.</div><div>The DNNF bridges the gap between advanced deep learning and practical usability, eliminating the need for expertise-dependent parameter tuning. Its efficiency, robustness, and simplicity make it a promising tool for real-world interferometric image processing, particularly in scenarios where traditional methods falter.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109134"},"PeriodicalIF":3.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240584","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":"Feasibility of underwater true color three-dimensional imaging using hyperspectral LiDAR","authors":"Yicheng Wang ,&nbsp;Hao Pan ,&nbsp;Shi Qiu ,&nbsp;Fashuai Li ,&nbsp;Yunhui Guo ,&nbsp;Boyu Liu ,&nbsp;Xinyuan Zhang ,&nbsp;Fei Han ,&nbsp;Yuwei Chen","doi":"10.1016/j.optlaseng.2025.109158","DOIUrl":"10.1016/j.optlaseng.2025.109158","url":null,"abstract":"<div><div>Hyperspectral LiDAR (HSL) has the advantage of integrating spatial and spectral detection and has become a new direction for underwater three-dimensional (3D) imaging. However, underwater HSL may encounter color distortion caused by the wavelength-selective attenuation property of the water medium. In order to address this problem, we propose the underwater target spectral radiometric correction (UWSRC) method. This method leverages the advantage of LiDAR in the acquisition of the ranging information for each point of the target. Based on the assumption of consistent water transmittance along the laser transmission path, the spectral transmittance of water at each point can be accurately calculated according to the ranging data. Then each point’s spectral reflectance can be corrected, achieving true color reconstruction of 3D point clouds of underwater targets. In order to assess the feasibility of the proposed method, we built a underwater virtual active HSL system to conduct underwater 3D imaging experiments in turbid water environment. The results indicate that the fidelity of the reconstructed colors is significantly improved, and the ranging accuracy has reached millimeter-level. This method can be easily applied to underwater true-color 3D imaging based on HSL and is also expected to be applied to true-color 3D imaging restoration in other transmission medium.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"194 ","pages":"Article 109158"},"PeriodicalIF":3.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240485","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}