Optics and Lasers in Engineering最新文献

{"title":"Advancing visual roughness measurement: A full-reference imaging approach for light source interference elimination","authors":"Enhui Lu ,&nbsp;Wenxiang Ren ,&nbsp;Hong Miu ,&nbsp;Xinglong Zhu ,&nbsp;Jian Liu","doi":"10.1016/j.optlaseng.2025.108910","DOIUrl":"10.1016/j.optlaseng.2025.108910","url":null,"abstract":"<div><div>Presently, variations in light source brightness significantly affect visual roughness measurement methods. To tackle this, a Full-reference imaging approach (FRI) is introduced to capture comprehensive light field information, encompassing incident and surface-reflected light. Utilizing the energy ratio between these fields minimizes light source interference and improves measurement accuracy. Initially, a relationship model, drawing upon Lambert-Beer and light scattering principles, correlates surface roughness with reflected and reference light energy. Theoretical feasibility is established, followed by validation of the model's robustness through numerical simulations. An FRI device is then developed to experimentally verify the model, showing a reduced impact of light source brightness on roughness measurements. Results demonstrate that the measurement system exhibits high stability and can detect a minimum roughness of 0.007 μm even with significant variations in light source brightness.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"188 ","pages":"Article 108910"},"PeriodicalIF":3.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480077","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 pilot study using flying spot laser thermography and signal reconstruction","authors":"Luca Santoro,&nbsp;Raffaella Sesana","doi":"10.1016/j.optlaseng.2025.108901","DOIUrl":"10.1016/j.optlaseng.2025.108901","url":null,"abstract":"<div><div>Active thermography (AT) has emerged as a critical non-destructive testing and evaluation (NDT&amp;E) technique for identifying subsurface defects in diverse industrial materials. Despite its widespread application, AT faces challenges such as inadequate heat input, noisy thermal signals, and non-uniform heating, which can obscure defect detection. This study introduces an enhanced approach leveraging flying spot laser thermography combined with advanced signal processing techniques to address these challenges. A meticulously designed calibration block, embedded with 180 spherical and rectangular notch defects of varying depths and dimensions, was fabricated using 3D printing to serve as the experimental model. The laser-induced thermal data were acquired at three distinct scanning speeds and underwent temporal alignment to synchronize heating events across all pixels. Principal Component Analysis (PCA) and Independent Component Analysis (ICA) were subsequently applied to the aligned datasets to extract and isolate defect-related thermal signatures. PCA effectively reduced data dimensionality and highlighted major thermal diffusion patterns associated with significant defects, particularly notched anomalies. However, its sensitivity diminished for smaller or deeper defects. In contrast, ICA provided a more refined separation of thermal signals, enhancing defect visualization and contrast, especially at slower scanning speeds where higher heat input improved thermal differentiation. Notably, ICA demonstrated superior performance in isolating notched defects compared to spherical ones due to pronounced thermal gradients. The findings underscore the potential of combining flying spot thermography with PCA and ICA to enhance defect detection and characterization in NDT&amp;E applications. Future work will focus on optimizing scanning parameters through simulation models and integrating machine learning algorithms to further improve the detection of smaller and shallower defects, thereby advancing the precision and efficacy of thermal analysis techniques.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"188 ","pages":"Article 108901"},"PeriodicalIF":3.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust centerline extraction method of laser stripe based on an underwater line scanning lidar","authors":"Xu Zhao ,&nbsp;Guojun Wu ,&nbsp;Guizhong Liu ,&nbsp;Zongxi Song ,&nbsp;Fei Feng ,&nbsp;Bo Liu ,&nbsp;Yafeng Wu","doi":"10.1016/j.optlaseng.2025.108898","DOIUrl":"10.1016/j.optlaseng.2025.108898","url":null,"abstract":"<div><div>The underwater line scanning lidar (ULSL), which can reconstruct the three-dimensional (3D) profile information of the underwater target from laser stripe images, plays an important role in seabed topography mapping, marine biological research, navigation and military targets detection, etc. The performance of the laser centerline extraction algorithm is crucial to the detection range and accuracy of ULSL. However, the poor optical environment conditions in seawater—the large attenuation and strong backscattering—will seriously hinder the extracting of laser centerlines with traditional algorithms for in-air images. For the ULSL, a special laser centerline extraction algorithm is urgently needed. For this reason, in this paper, an underwater line laser propagation model is established, which theoretically analyzes the energy distribution of the line laser along the propagation direction. On this basis, a distance gradient region energy (DGRE) method for underwater laser centerline extraction is proposed. The influence of backscattering is eliminated by distance gradient map, and the effect of the residual background noise is suppressed by distance gradient region energy map. As a result, the problem of inability to extract the laser centerline can be solved meanwhile mitigating the effects of backscatter and other background noise. Compared with other methods, our method can achieve a detection distance of 25.0 m with a detection accuracy of 50.0 mm under the water attenuation coefficient of <span><math><mn>0.28</mn><mo>/</mo><msup><mrow><mtext>m</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mi>@</mi><mn>532</mn><mspace></mspace><mtext>nm</mtext></math></span>, while other methods can only reach a maximum of 13.4 m. Finally, an underwater 3D reconstruction experiment was carried out, and a good 3D imaging capacity is realized with this method.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"188 ","pages":"Article 108898"},"PeriodicalIF":3.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480075","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":"AI-based autofocusing of red blood cells in digital in-line holographic microscopy","authors":"Jihwan Kim,&nbsp;Sang Joon Lee","doi":"10.1016/j.optlaseng.2025.108892","DOIUrl":"10.1016/j.optlaseng.2025.108892","url":null,"abstract":"<div><div>Autofocusing methods have been commonly utilized to measure depth positions of red blood cells (RBCs) from their holographic images captured by a digital in-line holographic microscopy (DIHM) system. However, conventional autofocusing methods have technical limitations in automatically and accurately determining the center of mass of biconcave RBCs positioned at different orientations. In this study, an artificial intelligence (AI)-based autofocusing method is proposed for precise measurement of depth positions of RBCs. Holographic images of RBCs captured at different depth positions and their corresponding focus value labels are used to train a convolutional neural network (CNN) model. The trained CNN model accurately evaluates focus values of RBC holograms, enabling the determination of depth positions of RBCs. Comparative analysis with conventional methods demonstrates superior autofocusing performance of the proposed AI-based autofocusing technique. The proposed technique would be utilized to analyze 3D dynamic behaviors of RBCs in complex 3D flows under various microfluidic conditions.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"188 ","pages":"Article 108892"},"PeriodicalIF":3.5,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471164","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":"High-speed active vision pose perception and tracking method based on Pan-Tilt mirrors for 6-DOF dynamic projection mapping","authors":"Shuangjiang Huang ,&nbsp;Fengnian Song ,&nbsp;Lihui Wang ,&nbsp;Yutao Huang ,&nbsp;Yuan He ,&nbsp;Shi Bai ,&nbsp;Tao Chen ,&nbsp;Masatoshi Ishikawa","doi":"10.1016/j.optlaseng.2025.108888","DOIUrl":"10.1016/j.optlaseng.2025.108888","url":null,"abstract":"<div><div>Active vision tracking projection mapping technology holds promise for augmented reality, autonomous driving, and robot navigation. However, it performs suboptimally with high-speed, randomly moving targets due to the difficulty in synchronizing accurate pose perception and high-dynamic vision tracking across a large field of view. Therefore, we proposed a high-speed active vision pose perception and tracking method for 6 degree-of-freedom (DOF) dynamic projection mapping. We designed a tracking method for an optical active vision system based on a Pan-Tilt mirror, which blends a pupil drift optical module field of view enhancement module and a Pan-Tilt optical axis control design, to achieve feedback control tracking of high-speed moving targets. The experimental results show that the tracking errors in the x and y directions are less than 25 pixels, and the maximum response time of the system is less than 5 ms. The projection position error is not more than 61.9 mm, and the rotation error is less than 4^∘. This method effectively achieves 6-DOF dynamic projection of high-speed moving targets, exhibiting enhanced accuracy and responsiveness in dynamic scenarios.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"188 ","pages":"Article 108888"},"PeriodicalIF":3.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444819","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":"Steady optical vortex beam enables extended depth of focus and robust data transmission in turbulence","authors":"Yiqian Yang,&nbsp;Liangcai Cao,&nbsp;Yidong Tan,&nbsp;Hongbo Sun","doi":"10.1016/j.optlaseng.2025.108889","DOIUrl":"10.1016/j.optlaseng.2025.108889","url":null,"abstract":"<div><div>Vortex beam (VB), which carry orbital angular momentum, offers significant potentials for high-efficiency and high-capacity data encoding. Robust propagation of VB in turbulence has garnered significant interests. However, their widespread adoption has been hindered by their sensitivity to turbulence-induced distortions, as their phase profiles are highly susceptible to distortions. In this work, we propose a steady optical vortex beam (STOVB) that integrates the properties of steady optical beams (STOB) with VB. STOVB achieves both an extended depth of focus and robust data transmission in turbulence, demonstrating a 17.6% reduction in intensity variation over time. This approach provides a promising pathway for high-resolution imaging and optical communication in challenging environments such as air, water, and other complex media.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"188 ","pages":"Article 108889"},"PeriodicalIF":3.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453368","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":"Development of high sensitivity shore-based laser induced fluorescence radar and its application in high-precision online monitoring of chlorophyll concentration","authors":"Yunfei Li ,&nbsp;Yanhu Fu ,&nbsp;Wanning Yi ,&nbsp;Yilin Zhao ,&nbsp;Yu-ze Song ,&nbsp;Fuhong Cai","doi":"10.1016/j.optlaseng.2025.108883","DOIUrl":"10.1016/j.optlaseng.2025.108883","url":null,"abstract":"<div><div>Monitoring aquatic chlorophyll is essential for environmental observation and the conservation of natural ecosystems, especially concerning the water quality in regions like lakefronts and coastlines, which are closely interrelated human activities. The development of shore-based devices capable of conducting high-frequency, high-precision, and automated chlorophyll detection is crucial. Optical sensing technology, distinguished by its exceptional specificity, sensitivity, and detection accuracy, is widely used in the field of water monitoring, involving the applications of reflectance and fluorescence spectral detection. Passive spectra detection can be affected by irregular variations in natural illumination, which needs to be corrected through calibration algorithms. Furthermore, water surface undulating and aquatic substances that can produce fluorescence besides chlorophyll can influence the original detection signal, increasing the complexity of the data processing. To overcome the above issues, this work presents a triple-mode shore-based sensing instrument. As the core of the system, the laser-induced fluorescence spectroscopy remote sensing system (LIFSRS) include active laser and imaging spectrometer with high sensitivity and excellent signal-to-noise ratio, along with an unsupervised processing algorithm. Its common path design ensures an accurate detection distance between detection systems and surface, while the compact transmissive diffraction configuration greatly minimize optical distortion due to the large detection aperture with in the imaging spectrometer. This setup effectively mitigates interference from extraneous fluorescence in the water without the need to subtract background fluorescence. The unsupervised algorithm demonstrates significant robustness and adaptability, capable of correcting the acquired fluorescence spectra based on the incident angle and detection distance. In addition, the instrument integrates a thermal imaging module and a millimeter wave radar module for bio-detection as well as for acquiring water surface temperature and altitude. Consequently, the system has been deployed at various locations across two cities, enabling the accurate acquisition of chlorophyll fluorescence concentrations in natural water bodies without the need for supervision. The detection time for a single measurement is 200 milliseconds, with the overall error percentage being minimal 15 %.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"187 ","pages":"Article 108883"},"PeriodicalIF":3.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437368","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":"Comparative performance of DIC and optical flow algorithms for displacement and strain analysis in laser beam welding","authors":"Viktor Savitsky ,&nbsp;Lennart Schmies ,&nbsp;Andrey Gumenyuk ,&nbsp;Michael Rehtmeier","doi":"10.1016/j.optlaseng.2025.108870","DOIUrl":"10.1016/j.optlaseng.2025.108870","url":null,"abstract":"<div><div>The measurement of strain and displacement in the context of the welding process represents a significant challenge. Optical methods, such as digital image correlation (DIC) or optical flow algorithms, have demonstrated their efficacy in robust and reliable data acquisition in harsh environments, including those encountered in welding processes. Concurrently, a trade-off between the accuracy of the measurement and the computational resources required for the associated calculations must be evaluated on a case-by-case basis. The application of filters to initial images represents a technique that serves to enhance the quality and accuracy of the strain and displacement prediction. In the present study, the estimated error of two algorithms, namely the Lucas-Kanade (LK) and the inverse compositional Gauss-Newton (IC-GN), is compared on the basis of both synthetic and real welding images. The displacement field is evaluated for different zones in the laser weld seam with varying contrast performance. Based on the aforementioned results, a strain calculation was conducted for both methods, which yielded comparable results for the LK and IC-GN algorithms</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"187 ","pages":"Article 108870"},"PeriodicalIF":3.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CFRP delamination defect detection by dynamic scanning thermography based on infrared feature reconstruction","authors":"Haoze Chen ,&nbsp;Jie Gao ,&nbsp;Zhijie Zhang ,&nbsp;Wuliang Yin ,&nbsp;Ningchen Dong ,&nbsp;Guangyu Zhou ,&nbsp;Zong Meng","doi":"10.1016/j.optlaseng.2025.108884","DOIUrl":"10.1016/j.optlaseng.2025.108884","url":null,"abstract":"<div><div>Shape information detection and evaluation of internal delamination defects in carbon fiber reinforced polymers (CFRP) is of great importance in industrial production and applications. In this paper, a new method for imaging and edge detection of internal delamination defects in CFRP using continuous line laser scanning excitation thermography is proposed. Firstly, a Following Laser Scanning Thermography (FLST) system is set up in the form of a heat source and camera that are stationary and the test piece is moving. It can perform fast and high-precision nondestructive testing of large workpieces. Subsequently, the advantages of FLST are utilized to reconstruct the infrared images of defects by simple feature lines, and the effects of different parameters on the reconstructed images are analyzed. Finally, the morphological information characterization of internal delamination defects in CFRP is realized by motion blur removal method combined with edge detection algorithm. The results demonstrate that the use of FLST system, combined with image reconstruction and motion blur removal method has high accuracy and efficiency in the non-destructive testing and evaluation of delamination defects.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"187 ","pages":"Article 108884"},"PeriodicalIF":3.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445731","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":"Holographically marked metasurface towards multi-user authentication","authors":"Shangying Zhou,&nbsp;Sheng Wang,&nbsp;Zhenyu Zhang,&nbsp;Bijun Xu,&nbsp;Xiaogang Wang","doi":"10.1016/j.optlaseng.2025.108836","DOIUrl":"10.1016/j.optlaseng.2025.108836","url":null,"abstract":"<div><div>Metasurface-based image encryption is becoming an increasingly prevalent trend in optical security; yet, limited attention has been directed towards metasurface-based image authentication. Here, we present a holographically marked metasurface for multi-user authentication based on polarization multiplexing technology. Through embedding a holographic marker in the metasurface via a different polarization channel, it simplifies the distinction between different metasurfaces, while simultaneously achieving multi-user authentication. In the authentication process, only by applying the correct authentication keys to the metasurface can the verifiable images be reconstructed. Computer simulation results confirm the feasibility and security of the proposed metasurface-based security approach.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"186 ","pages":"Article 108836"},"PeriodicalIF":3.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438014","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}