Optics and Lasers in Engineering最新文献

{"title":"High-fidelity optical section with digital mask filter: a structured illumination microscopy enhanced by confocal strategy","authors":"Xiaohang Duan ,&nbsp;Junyi Chen ,&nbsp;Nan Wang ,&nbsp;Yong Yang","doi":"10.1016/j.optlaseng.2025.109599","DOIUrl":"10.1016/j.optlaseng.2025.109599","url":null,"abstract":"<div><div>Optical sectioning structured illumination microscopy (OS-SIM) faces limitations in background suppression under low signal-to-noise ratio (SNR) conditions, where out-of-focus noises and scattered light degrade sectioning abilities. To address this limitation, we introduce confocal-inspired optical sectioning structured illumination microscopy (COS-SIM), which integrates confocal-like spatial filtering into the OS-SIM framework to simultaneously process information in both spatial and frequency domains. It replaces conventional sinusoidal illumination with dynamically programmable digital masks generated by a spatial light modulator (SLM) and incorporates conjugate virtual digital masks at the detection plane. By controlling the duty cycle, COS-SIM enables parallelized virtual pinhole array detection for enhanced background rejection, while frequency-domain demodulation yields enhanced optical sectioning performance.This approach retains the high-speed, widefield detection advantage inherent to OS-SIM. Theoretically, COS-SIM maintains axial resolution equivalent to that of OS-SIM, but significantly improves optical sectioning quality through optimized duty-cycle control of the mask patterns, which reduces residual background noise. Experimentally, COS-SIM achieves a depth of field consistent with OS-SIM while yielding superior signal-to-background ratio (SBR) and signal-to-noise ratio (SNR). These results confirm that COS-SIM offers enhanced sectioning fidelity in the presence of strong background signals, extending the applicability of structured illumination microscopy to challenging scenarios such as integrated circuit inspection and metallographic sample detection.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109599"},"PeriodicalIF":3.7,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928046","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":"Multiparameter sensing by permanent macrobending deformation","authors":"João Preizal ,&nbsp;Ricardo Oliveira","doi":"10.1016/j.optlaseng.2025.109593","DOIUrl":"10.1016/j.optlaseng.2025.109593","url":null,"abstract":"<div><div>This work presents a novel interferometric structure based on two single-mode fibers twisted and fused in a helical structure through a commercial CO₂ laser processing station. The resulting device induced macrobending effects that promote light coupling from the core to the cladding and vice versa, creating an interferometric pattern in the transmission spectrum due to the phase difference between the light travelling in the core and cladding regions. The influence of the twist period on the spectral response showed an increased attenuation and higher fringe contrast for shorter twist periods, i.e., low bending radius. The sensing capabilities of the structure were evaluated for torsion, strain, and temperature, yielding sensitivities of −0.49 nm/(rad/m), –8.8 pm/με, and –81 pm/ °C, respectively. Temperature cross-sensitivity was also evaluated, showing values of 0.17 (rad/m)/ °C for torsion and 9 με/ °C for strain. These results highlight the potential of the structure for torsion sensitivity with high sensitivity and low cross-sensitivity. Therefore, this work demonstrates as well that these parameters can be measured using conventional single-mode fiber structures instead of complex and more expensive optical fibers, thereby reducing both cost and system complexity through a simpler and automated fabrication process compared with other fiber-optic sensors.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109593"},"PeriodicalIF":3.7,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928047","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":"Optimized complex fields for non-iterative generation of phase holograms","authors":"Valentina Lobo-Ruiz,&nbsp;Alejandro Velez-Zea,&nbsp;John Fredy Barrera-Ramírez","doi":"10.1016/j.optlaseng.2025.109584","DOIUrl":"10.1016/j.optlaseng.2025.109584","url":null,"abstract":"<div><div>This work presents a non-iterative method for generating high-quality phase-only holograms based on the optimization of a complex field. To achieve this, an initial complex field is defined such that its product with a target amplitude yields an approximate phase-only hologram of the target after backward propagation. The complex field is then optimized using stochastic gradient descent to minimize a loss function, calculated between each hologram reconstruction and the corresponding target amplitude over a large image database. This enables the use of the optimized complex field (OCF) as a universal pre-computed function for the fast, non-iterative generation of holograms for any target. Numerical evaluations demonstrate that holograms generated with the OCF achieve superior reconstruction quality, as measured by correlation coefficient, mean squared error, and structural similarity, compared to those generated using random phase and optimized Fresnel random phase (OFRAP) methods across various epochs and propagation distances. The effectiveness of the proposed OCF method is further validated through experimental demonstrations in a holographic projection setup using a phase-only spatial light modulator.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109584"},"PeriodicalIF":3.7,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928048","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":"Ultrahigh-Q plasmonic-photonic resonances with subwavelength confinement enabled by bound states in the continuum","authors":"Shijia Cheng ,&nbsp;Hanyue Liu ,&nbsp;Kaiyang Wang ,&nbsp;Qifeng Ruan ,&nbsp;Qiao Jiang ,&nbsp;Zhiyuan Gu","doi":"10.1016/j.optlaseng.2026.109605","DOIUrl":"10.1016/j.optlaseng.2026.109605","url":null,"abstract":"<div><div>Plasmonics, featured with enhanced light-matter interaction and strong wave localization, have been intensively studied theoretically and experimentally in the past few decades. However, the intrinsic ohmic loss in plasmonic-based devices is a challenging issue that limits the performance of such configurations, hindering their application potential. Herein, we propose a simple and effective strategy to achieve optical resonances with ultrahigh quality (<em>Q</em>) factors (∼ 10⁴) and subwavelength confinement (∼ λ²/20) in hybrid plasmonic-photonic structures. The proposed design consists of a silicon superstrate and silver substrate which are separated by a thin silica spacer, forming a composite waveguide layer that supports hybrid plasmonic-photonic guided modes (GMs) with ultrasmall mode area. By patterning low-index polymer gratings onto the stacked films, the obtained GMs can be effectively turned into guided mode resonances with ultrahigh <em>Q</em> factors. Leveraging this strategy, ultrasmall mode area far beyond the diffraction limit can be realized without sacrificing <em>Q</em> factors. Such findings provide a new paradigm to design high-performance plasmonic elements, which may show superiority in nonlinear optics, lasers, and sensors.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109605"},"PeriodicalIF":3.7,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928044","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":"Enhanced three-dimensional phase computed tomography with morphological adaptation for complex polymer fiber characterization","authors":"E.Z. Omar","doi":"10.1016/j.optlaseng.2025.109582","DOIUrl":"10.1016/j.optlaseng.2025.109582","url":null,"abstract":"<div><div>This work presents a novel and enhanced reconstruction method for three-dimensional phase computed tomography specifically designed to reconstruct complex volumetric phase distributions in specimens with severe geometric discontinuities, such as necked regions and surface crazing. Conventional filtered back projection (FBP) algorithms exhibit fundamental limitations, including severe streak artifacts, geometric distortions, and inadequate sampling, when applied to such non-ideal geometries. To overcome these challenges, the proposed methodology uses continuous wavelet transforms to extract phase data from polarizing microscopy. It then employs topology-aware sinogram construction with weighted multi-slice interpolation. Advanced reconstruction algorithms incorporate multi-dimensional regularization through inter-slice continuity constraints and three-dimensional morphological adaptation using geometry-specific Gaussian kernels. Artifacts are suppressed through automated boundary detection and craze identification algorithms. The methodology is experimentally validated using a Pluta polarizing interference microscope and a high-precision rotational stage to acquire interferometric data from isotactic polypropylene (iPP) and polypropylene (PP) fibers encompassing undrawn, necked, and crazed morphologies. Quantitative analysis demonstrates a significant performance improvement over traditional FBP, with error reductions of 20% for regular fibers, 49% for necked fibers, and 53% for crazed fibers, all measured relative to ground truth distributions. The reconstructed 3D phase maps are quantitatively converted to birefringence distributions, revealing distinct microstructural changes induced by drawing, necking, and crazing. This framework provides precise 3D analysis for better quality control of advanced materials.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109582"},"PeriodicalIF":3.7,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928028","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":"Application-driven multi-modal depth completion in fringe projection profilometry","authors":"Badrinath Balasubramaniam ,&nbsp;Vignesh Suresh ,&nbsp;Yang Cheng ,&nbsp;Jiaqiong Li ,&nbsp;Beiwen Li","doi":"10.1016/j.optlaseng.2025.109587","DOIUrl":"10.1016/j.optlaseng.2025.109587","url":null,"abstract":"<div><div>Fringe projection profilometry (FPP), while capable of sub-millimeter accuracy at kilohertz speeds, produces sparse and incomplete depth maps when scanning objects with complex, heterogeneous material properties including specular metallic surfaces, mirror-like reflective regions, and absorptive materials. This is due to measurement failures predominantly in mirror-like reflective regions and underexposed areas where fringe patterns are unreliable or absent. Hard disk drives represent a particularly challenging test case for these limitations, exhibiting all of these problematic surface characteristics within a single assembly. Accurate 3D sensing of such components is critical for automated robotic disassembly in e-waste recycling, where valuable materials such as palladium, aluminum, and the rare earth metal neodymium remain largely unrecovered due to lack of recycling infrastructure. Recent zero-shot depth estimation models, while inaccurate for fine-scale, millimeter-level depth prediction, capture useful geometric priors. In this research, we present a multi-modal fusion approach that combines three data sources: sparse depth map computed from FPP, projector-illuminated grayscale image, and the relative depth map from the Depth Anything v2 Foundation Model. Our lightweight fusion network exploits the lower domain gap in geometric features compared to appearance features, enabling effective learning and sim-to-real transfer with limited synthetic and real-world training data. The network learns to predict dense depth in regions where FPP fails, which is then fused with the original sparse measurements to produce complete depth maps. We demonstrate that this approach achieves a mean absolute error and root mean square error of less than 2 mm on both synthetic and real-world test cases, and critically, achieves good reconstruction fidelity in the sparse regions, paving the way for fine-scale robotic disassembly while avoiding the need for extensive surface treatment or large-scale real-world data collection. Furthermore, our approach addresses the primary limitations of FPP on mirror-like reflective surfaces and underexposed regions within a single scan, and demonstrates a potential roadmap for industrial metrology of parts with similarly challenging optical properties.</div><div>The code for our multi-modal depth completion network, MMDC-Net, will be publicly available at <span><span>https://github.com/badri999/MMDC-Net</span><svg><path></path></svg></span></div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109587"},"PeriodicalIF":3.7,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927888","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":"Stokes vector-based mamba for low-light color polarimetric image enhancement","authors":"Meiling Gao ,&nbsp;Guangyu Zhao ,&nbsp;Xuedong He ,&nbsp;Xiaoyu Jin ,&nbsp;Jin Duan ,&nbsp;Huilin Jiang","doi":"10.1016/j.optlaseng.2025.109595","DOIUrl":"10.1016/j.optlaseng.2025.109595","url":null,"abstract":"<div><div>To address the challenges of severe noise interference, insufficient global degradation capture, and artifact-prone enhancement in low-illumination division-of-focal-plane (DoFP) color polarimetric images, we propose StokesMamba, a dual-branch low-light color polarimetric image enhancement method based on Mamba and Stokes vector representations. First, a linear irradiance compensation is applied to the degraded Stokes vector, with a scaling factor γ used to enhance signal amplitude, mitigating feature masking caused by low signal-to-noise ratio (SNR). Subsequently, a dual-branch enhancement structure is designed based on the distinct physical properties of the Stokes components: the S0 branch combines adaptive intensity compression in the horizontal/vertical-intensity (HVI) color space with the denoising block (DB) module and intensity Mamba (IMamba) for artifact-free brightness enhancement, while the S1,2 branch leverage the gradient characteristics of differential images, incorporating the DB module and polarization Mamba (PMamba) to enhance edge and detail features. Experimental results demonstrate that our method outperforms existing approaches on the LLCP and PLIE datasets, achieving superior performance in terms of PSNR, SSIM, and visual quality.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109595"},"PeriodicalIF":3.7,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928045","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":"Quantitative raman thermometry and N2+ detection in a non-transferred plasma torch","authors":"Sebastian Nilsson ,&nbsp;Aurélien Ivanoff ,&nbsp;Alsu Zubairova ,&nbsp;Likitha Siddanathi ,&nbsp;Alexey Sepman ,&nbsp;Henrik Wiinikka ,&nbsp;Lars-Göran Westerberg ,&nbsp;Marcus Aldén ,&nbsp;Christian Brackmann ,&nbsp;Andreas Ehn","doi":"10.1016/j.optlaseng.2025.109583","DOIUrl":"10.1016/j.optlaseng.2025.109583","url":null,"abstract":"<div><div>Quantitative laser-based diagnostics like Raman spectroscopy are essential for studying high-temperature processes, but their application in intensely luminous and transient environments such as plasma torches is severely limited by overwhelming background emission. This study focuses on the quantitative thermometry of a 7 kW atmospheric air plasma jet, an environment where such measurements are notoriously difficult. To enable these measurements, a Polarization Lock-In Filtering (PLF) Raman technique is used to suppress the intense and fluctuating plasma background. The method successfully yields high-quality N₂ ro-vibrational spectra along the jet’s central axis. Model-based fitting of these spectra produces a detailed axial temperature profile, showing a decay from over 3700 K near the nozzle. Furthermore, the high signal quality enabled the detection of singly ionized nitrogen (N₂⁺) in the plasma core, providing direct evidence of its ionized state. These results represent the first application of PLF for thermometry in a plasma torch and provide critical experimental data for validating magnetohydrodynamic simulations.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109583"},"PeriodicalIF":3.7,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928030","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":"Spectrum aggregation method for spectral mismatch in high-speed MEMS micromirror scanning FMCW LiDAR","authors":"Fu Zhu ,&nbsp;Chen Wang ,&nbsp;Guixiang Chen ,&nbsp;Wenwen Zhang ,&nbsp;Weiji He ,&nbsp;Qian Chen","doi":"10.1016/j.optlaseng.2025.109567","DOIUrl":"10.1016/j.optlaseng.2025.109567","url":null,"abstract":"<div><div>We propose a spectrum aggregation method to address the inherent incompatibility between resonant MEMS micromirrors and FMCW LiDAR systems. This issue caused by the mismatch between high-speed resonant scanning and the stable sampling requirement of FMCW signals. The mismatch leads to spectral broadening and depth estimation precision degrading, limiting the application of MEMS-based scanners in FMCW LiDAR. Our spectrum aggregation method involves a dynamic model of the MEMS micromirror paired with a signal-level compensation algorithm, enabling equivalent uniform sampling within each chirp cycle while maintaining the resonant scanning mechanism. This solution effectively mitigates spectral distortion and enhances scanning stability, achieving a uniform angular resolution of 0.125^∘ × 0.18^∘ across a 25^∘ × 36^∘ field of view. The method ensures high-depth estimation accuracy, with precision dropping from 1.34 mm in a single-point system without scanning devices to 1.5 mm. This approach provides a practical, cost-effective solution for high-precision FMCW LiDAR, making it suitable for applications in autonomous robotics, mobile sensing, and intelligent environmental perception.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109567"},"PeriodicalIF":3.7,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928029","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":"A dual-camera coded aperture snapshot spectral imager using a reflective mask","authors":"Xinyu Liu,&nbsp;Liangcai Cao","doi":"10.1016/j.optlaseng.2025.109600","DOIUrl":"10.1016/j.optlaseng.2025.109600","url":null,"abstract":"<div><div>The coded aperture snapshot spectral imager (CASSI) acquires compressive measurements of spectral images in a single exposure, which are then reconstructed into full data cubes using compressive sensing algorithms. However, the reconstruction quality is limited by the severely underdetermined mechanism in the compressive measurements. In this work, a dual-camera CASSI configuration using a reflective mask is proposed, enabling simultaneous capture of a grayscale image alongside the encoded spectral measurement. Unlike available dual-camera CASSI, our arrangement ensures pixel-level alignment and effective data fusion between the two arms. A multi-scale fusion network (MSF-Net) is developed to integrate the high-spectral-resolution CASSI measurement and the high-spatial-resolution grayscale image. The proposed reflective dual-camera CASSI (RDC-CASSI) with the MSF-Net offers efficient acquisition and reconstruction of spectral image cubes with high-spatial and high-spectral resolution. The peak signal-to-noise ratio and structural similarity index measure of the RDC-CASSI are 6.96% and 1.16% higher than those of the dual-disperser CASSI, respectively. The reconstructed spectrum of the standard color chart closely matches the ground truth from a commercial spectroradiometer, with an average mean squared error of 0.007. The improvements demonstrate a practical and scalable solution for real-time, high-quality spectral imaging.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"200 ","pages":"Article 109600"},"PeriodicalIF":3.7,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886039","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}