Wei Liu , Siying He , Jingxuan Xu , Yongzhen Chen , Wanqing Li , Hong Shu , Puhong Duan , Fang Zhu
{"title":"Underwater image enhancement based on adaptive information transfer and weighted stationary wavelet perception fusion","authors":"Wei Liu , Siying He , Jingxuan Xu , Yongzhen Chen , Wanqing Li , Hong Shu , Puhong Duan , Fang Zhu","doi":"10.1016/j.optlastec.2025.113625","DOIUrl":"10.1016/j.optlastec.2025.113625","url":null,"abstract":"<div><div>Underwater images commonly suffer from issues like color distortion, low contrast, and blurred details. To tackle these degradation problems, we propose an underwater image enhancement (UIE) method named ATWF, which is based on adaptive information transfer and weighted stationary wavelet perception fusion. This method firstly introduces an adaptive information transfer strategy, grounded in histogram similarity cue, to effectively compensate for the attenuation channels. Subsequently, it integrates linear stretching to increase the dynamic range of color compensated image. Secondly, an adaptive gamma correction algorithm is used to enhance the overall contrast of the color-corrected image, and a multi-scale side window box filter (SWBF) technique is employed to improve its local details simultaneously. Finally, the stationary wavelet transform is used to decompose the enhanced images into low-frequency (LF) and high-frequency (HF) components. Perception fusion rules tailored to the different characteristics of each component are devised to improve the visual quality of the resultant image. Experiments on multiple public datasets show that: (1) ATWF can effectively correct color distortion; (2) it significantly improves image contrast, suppresses noise, and highlights details; (3) in terms of qualitative and quantitative evaluation, corner detection, image matching, and image segmentation, it outperforms or is comparable to other mainstream UIE methods. Additionally, ATWF demonstrates strong generalization ability in various complex degradation scenarios.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113625"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Robust interferogram processing using deep learning and signal subspace method for phase derivative estimation","authors":"Viren S Ram , Rajshekhar Gannavarpu","doi":"10.1016/j.optlastec.2025.113616","DOIUrl":"10.1016/j.optlastec.2025.113616","url":null,"abstract":"<div><div>For non-destructive deformation metrology using optical interferometry, the derivative of phase map encoded in the interferogram signal contains crucial information about physical quantities such as displacement derivatives and strain. Hence, reliable retrieval of phase derivative is of great practical significance in precision metrology. However, this information is often difficult to retrieve in the presence of severe noise and imaging artifacts such as non-uniform intensity variations. In this paper, we propose a deep learning assisted signal subspace approach for extracting phase derivatives. The main advantages of the proposed method include robustness against severe noise and tolerance against interferogram abnormalities. The performance of the proposed method is validated using rigorous numerical simulations. The practical utility of the method is shown via experimental results obtained in digital holographic interferometry.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113616"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Research on real-time gear fault detection and classification technology based on EFPI vibration sensor","authors":"Zexin Li , Shengpeng Wan , Junsong Yu","doi":"10.1016/j.optlastec.2025.113627","DOIUrl":"10.1016/j.optlastec.2025.113627","url":null,"abstract":"<div><div>In order to detect the health status of gears working for long periods of time in harsh environments such as high speed and high load, this paper studies the real-time detection and classification technology of gear faults based on fiber-optic extrinsic Fabry-Perot interferometer (EFPI) vibration sensors. A deep learning model of 1D-LSAM-CNN-BiLSTM is proposed to improve the accuracy and speed of gear fault classification. Firstly, three different types of gears are prepared, each including a health gear, a wear gear, and a tooth breakage gear. Then, a feedback based single wavelength intensity demodulation EFPI system is used to collect vibration signals for 27 gear fault categories. The collected vibration signals are transmitted to the computer through the ACM8211 gigabit ethernet module and stored. The 1D-LSAM-CNN-BiLSTM deep learning model automatically reads stored data, preprocesses and trains it. The trained model can perform real-time fault classification on the collected vibration signals. The experimental results show that the real-time gear fault detection and classification system proposed in this paper has high recognition accuracy.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113627"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Vasil’ev , M. Zhezhu , H. Parsamyan , G. Baghdasaryan , M. Sargsyan , D.A. Ghazaryan , H. Gharagulyan
{"title":"Revisiting THz absorption in GO and rGO liquid crystalline films","authors":"A. Vasil’ev , M. Zhezhu , H. Parsamyan , G. Baghdasaryan , M. Sargsyan , D.A. Ghazaryan , H. Gharagulyan","doi":"10.1016/j.optlastec.2025.113628","DOIUrl":"10.1016/j.optlastec.2025.113628","url":null,"abstract":"<div><div>With a swift progress in modern high-throughput communication systems, security, sensing and medicine utilizing THz range technologies, the demand for easy-to-fabricate, lightweight and high-performance absorbing materials has increased drastically. Notably, traditional approaches of eliminating unwanted radiation based on metasurfaces often face fabrication challenges limiting their practicality. In this study, we propose a straightforward approach for fabricating graphene oxide (GO) and reduced graphene oxide (rGO) liquid crystalline (LC) films <em>via</em> the vacuum filtration method and investigate their THz absorption characteristics. Here, the presence of LC phase in our electrochemically exfoliated GO and rGO LC films was confirmed by ellipsometric characterization. THz time-domain spectroscopy (TDS) measurements reveal that these films possess a low reflectance and transmittance confirming their strong absorptive properties within 0.4–1.6 THz frequency range for ∼ 2 μm thick GO and rGO LC films. Particularly, the GOLC film shows ∼ 37 % average absorption at a thickness of 2.12 µm, which is 221 times smaller than the central wavelength. Similarly, the rGOLC film reaches ∼ 50 % absorption with a 1.68 µm thickness, 279 times smaller than the central wavelength. These findings provide valuable insights for development of GO- and rGO-based LC THz absorbers with highly tunable properties due to the ordering of GO flakes. Specifically, the LC phase of GO contributes to the formation of more uniform films with enhanced absorption due to the compact stacking and denser packing, compared to conventional GO films with randomly oriented GO flakes..</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113628"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haiyang Xie , Pengrun Ying , Binxin Wang , Ruixin Tang , Ziyu Luo , Yijun He , Hui Liu
{"title":"Bidirectional ytterbium-doped fiber laser with independent nonlinear-polarization-rotation mode-locking and gain medium","authors":"Haiyang Xie , Pengrun Ying , Binxin Wang , Ruixin Tang , Ziyu Luo , Yijun He , Hui Liu","doi":"10.1016/j.optlastec.2025.113574","DOIUrl":"10.1016/j.optlastec.2025.113574","url":null,"abstract":"<div><div>This paper presents a bidirectional mode-locked ytterbium-doped fiber laser with independent nonlinear polarization rotation (NPR) mode-locking and gain medium. This laser achieves robust bidirectional NPR mode-locking operation without the need for condition of saturation critical power and enables a direct and wide range control over the repetition frequency difference (0–38 kHz). The pulse energy reaches up to 2.8 nJ. The long-term fluctuation of the repetition rates is well-consistent, resulting in a stable repetition rate difference with standard deviation of 0.8 Hz while the repetition rate varies as large as 180 Hz. The intensity noise correlation and phase noise consistency are measured, revealing the complex noise behaviors in detail and the room for enhancing the mutual coherence. The interferograms are observed and Fourier transformed, resulting in a spectrum that is consistent with the optical spectra. This work offers an alternative solution for the bidirectional fiber mode-locked laser with pulse energy in the nanojoule range that benefits both linear and nonlinear dual-comb applications.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113574"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chun Meng , Xu-Hui Bao , Yu-Xuan Ren , PanPan Yu , Fengya Lu , Jinhua Zhou , Min-Cheng Zhong
{"title":"Orbiting microparticle dimer with symmetry-breaking on photothermal Marangoni flow","authors":"Chun Meng , Xu-Hui Bao , Yu-Xuan Ren , PanPan Yu , Fengya Lu , Jinhua Zhou , Min-Cheng Zhong","doi":"10.1016/j.optlastec.2025.113618","DOIUrl":"10.1016/j.optlastec.2025.113618","url":null,"abstract":"<div><div>Light-fueled microparticle rotors, capable of continuous rotation under a static light source, hold significant potential for applications in optically driven micromachines, microfluidics, particle transport, and soft-matter nonlinear optics. However, achieving high-speed and directional rotation of microparticles using a static low-power-density light source remains a challenge. We propose asymmetric Marangoni flow to drive the rapid rotation of microparticles, and demonstrate that a dimeric active microparticle (DAP) exhibits high-speed directional rotation in a low-power-density annular optical trap at the water–air interface. The driving force arises from the asymmetric Marangoni flow induced by the non-uniform laser heating of the DAP. The average linear velocity of the DAP rotation is regulated by the laser power. Furthermore, the enhanced asymmetry results in larger rotation speed, which is experimentally corroborated by polystyrene sphere with larger diameter. The rotation speed of the particle depends on the competition between the increase in the viscous drag force in Marangoni flow and the increase in the viscous drag force in still water. Finally, the asymmetric Marangoni flow is successfully utilized to drive the rotation of trimeric active microparticles and cell-carrying DAPs. This technology, characterized by its low power density and small temperature rise, demonstrates promising potential for applications in active matter, microscale robotics, and drug/cell delivery microsystems.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113618"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hong-yun He , Hong-wen Deng , Yi Hu , Xu Cheng , Yu-dai Wang , Bing-bing Zhang
{"title":"Influence of process parameters on bubble formation and melt pool dynamics during laser directed energy deposition via in-situ synchrotron X-ray imaging","authors":"Hong-yun He , Hong-wen Deng , Yi Hu , Xu Cheng , Yu-dai Wang , Bing-bing Zhang","doi":"10.1016/j.optlastec.2025.113611","DOIUrl":"10.1016/j.optlastec.2025.113611","url":null,"abstract":"<div><div>Process parameters play a crucial role in the formation of pore defects in laser directed energy deposition of titanium alloy components; these defects significantly compromise the fatigue performance of the components. The pore defects always originate from trapped bubbles. However, most studies focused on post-analysis for pore defects after solidification. There are limited investigations on the influence of process parameters on bubble formation and retention during deposition using real-time observation. In this paper, the influence of laser power and scanning speed on both bubble formation and melt pool dynamics was studied via in-situ synchrotron X-ray imaging and numerical simulation. The formation, escape, and retention of bubbles during deposition process were quantitatively analyzed. Results show that the number of introduced and residual bubbles increased with increasing laser power (from 300 W to 400 W), but the residual bubble ratio initially increased and subsequently decreased. This trend is attributed to the enhancement of both Marangoni flow and heat input caused by increasing laser power. The stirring effect induced by the Marangoni flow not only enhances the introduction of bubbles but also facilitates their escape. Meanwhile, higher heat input prolonged the retention time of the melt pool, which benefits bubble escape. The residual bubble number was high under slow scanning speed of 500 mm/min, which can be attributed to the sustained downward inner gas pressure exerted by the laser beam on the bubbles.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113611"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qi Yu , Zhanfeng Li , Yu Hua , Xiaohu Yang , Chunying Zhang , Yue Li , Xiaoxi Li , Tianjiao Li
{"title":"On-Orbit High-Precision spectral correction based on the Mie scattering","authors":"Qi Yu , Zhanfeng Li , Yu Hua , Xiaohu Yang , Chunying Zhang , Yue Li , Xiaoxi Li , Tianjiao Li","doi":"10.1016/j.optlastec.2025.113516","DOIUrl":"10.1016/j.optlastec.2025.113516","url":null,"abstract":"<div><div>High-precision spectral calibration is crucial for ensuring the quality of spectral data in on-orbit spectrometer operations. While the detected light typically enters the spectrometer system at normal incidence, the calibration light source often enters at oblique angles, which can significantly affect calibration results. Experimental observations indicate that oblique incidence causes variations in the energy distribution at the spectrometer’s entrance pupil, with the non-uniformity of this distribution identified as the primary cause of spectral drift. However, modelling diffuser plates remains inherently challenging due to the randomness introduced during their fabrication process. To address this, the present study develops a spectral calibration model based on Mie scattering theory and analyses the causes of spectral drift. By systematically analysing the diffuser plates and optical structures within the calibration system, it is found that the oblique angles of the calibration light source and the particle sizes of the diffuser plates are critical factors influencing calibration accuracy. Additionally, the impact of wavelength on spectral drift is predicted, providing a method for correcting high-precision on-orbit spectral calibration. This study offers a robust theoretical foundation and practical approach to enhance the calibration accuracy of on-orbit spectrometers.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113516"},"PeriodicalIF":4.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-directional sub-aperture wrapped phase aberration compensation for synthetic aperture digital holographic microscopy using deep learning","authors":"Liu Huang, Zhiwei Wang, Benyong Chen, Xiaping Fu","doi":"10.1016/j.optlastec.2025.113595","DOIUrl":"10.1016/j.optlastec.2025.113595","url":null,"abstract":"<div><div>The sensitivity of quantitative phase to subtle changes in the optical field makes synthetic aperture (SA) and phase retrieval affected by optical aberrations, limiting the imaging signal-to-noise ratio, reconstructed image quality and spatial resolution of synthetic aperture digital holographic microscopy (SA-DHM). In this paper, the constructed SA-DHM uses Digital Micromirror Device (DMD) to form the multi-directional oblique illumination (OI) and obtain a set of complementary apertures containing different spatial frequency information. A multi-directional sub-aperture wrapped phase aberration compensation method based on Moga-enhanced ConvNeXt architecture is proposed, and multiple multi-order gated aggregation blocks are integrated to directly construct the mapping relationship between the sub-aperture wrapped phase maps and the Zernike polynomial coefficients. A hybrid simulation dataset covering various types of micro/nano samples and phase aberrations is created, and a data augmentation method based on random linear combinations is introduced to enhance sample diversity and network generalization capability. Simulation and experimental results show that the proposed method achieves rapid and accurate aberration compensation and baseline unification of each sub-aperture prior to SA processing, enabling high-quality sub-aperture spectrum stitching and 1.87× super-resolution phase imaging, while eliminating the need for carrier frequency estimation, exact system parameters, or residual aberration correction.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113595"},"PeriodicalIF":4.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Simulation-based optimization of dark current influenced by device parameters in InAs/GaSb LWIR detectors","authors":"Yaqi Zhao , Xiaoning Guan , Jinyi Cheng , Fan Zhang , Dongwei Jiang , Donghai Wu , Feng Zhou , Pengfei Lu","doi":"10.1016/j.optlastec.2025.113513","DOIUrl":"10.1016/j.optlastec.2025.113513","url":null,"abstract":"<div><div>We presented the performance optimization of a pBiBn type-Ⅱ superlattice (T2SL) long-wavelength infrared detector. Through numerical simulations, we investigated how changes in device structure parameters (such as doping levels and layer thickness) affect electrical properties, including the energy band and dark current density of the pBiBn long-wavelength infrared detector. Based on semiconductor physics, including energy band structure and depletion region, we analyzed and explained the underlying mechanisms of these effects. As a result, we identified a set of optimal device structure parameters. The designed long-wavelength infrared detector incorporates two barriers, which effectively reduce the dark current. Simulation results show that the dark current density of our optimized InAs/GaSb double-barrier long-wavelength infrared detector, with an absorber layer T2SL bandgap of 0.0972 eV, can reach 1.27×10<sup>−4</sup> A/cm<sup>2</sup> at 77 K and V<sub>bi</sub>= -100 mV, with the depletion zone width on the absorber layer side reduced to nearly zero.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113513"},"PeriodicalIF":4.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}