Optics and Laser Technology最新文献

{"title":"Tailored adaption of thermal diffusion by ablation cooling on polymers through unique dependence on laser repetition rate","authors":"Andrés P. Bernabeu ,&nbsp;Daniel Puerto ,&nbsp;José Reyna ,&nbsp;Jorge Francés ,&nbsp;Andrés Márquez ,&nbsp;Inmaculada Pascual ,&nbsp;Sergi Gallego ,&nbsp;Augusto Beléndez","doi":"10.1016/j.optlastec.2025.113949","DOIUrl":"10.1016/j.optlastec.2025.113949","url":null,"abstract":"<div><div>High repetition rate femtosecond laser processing reduces thermal effects through ablation cooling. This often-overlooked effect occurs when ablation is induced in the heat accumulation regime, typically associated with the GHz repetition rate regime, where undesirable shielding effects occur. However, the low thermal diffusivity and phase transition temperatures of polymers enable ablation cooling to be observed at lower repetition rates (&lt;1 MHz), while preventing shielding effects. Separating these phenomena offers insights into ablation cooling effects that are applicable to a broader range of materials in GHz regimes. This work analyzes the thermal and ablative effects on poly(ethylene terephthalate) (PET) surfaces resulting from high repetition rate (10 kHz – 1 MHz) femtosecond (450 fs) laser irradiation at <em>λ</em> = 515 nm, for different fluences (0.91 – 1.68 J/cm²) and pulse numbers (200 – 400). The results evidence that extended thermal diameters decrease at higher repetition rates (∼1 MHz) compared to the 40 – 100 kHz regime due to ablation cooling, resulting in more optimal processing. This effect is independent of fluence and pulse number, being influenced only by repetition rate. A thermal model explains the reduction of thermal effects and saturation of ablation diameters, serving as a predictive tool for modifications induced at high repetition rates.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113949"},"PeriodicalIF":5.0,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219875","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":"Multimodal photoacoustic-fluorescence microscopy for quantitative absorption coefficient mapping and precision lesion tracking in disease models","authors":"Linghui Gong ,&nbsp;Zhaoyu Wang ,&nbsp;Yidang Zhang ,&nbsp;Zequan Xu ,&nbsp;Hai Lin ,&nbsp;Chao Cai ,&nbsp;Yubin Liu","doi":"10.1016/j.optlastec.2025.113940","DOIUrl":"10.1016/j.optlastec.2025.113940","url":null,"abstract":"<div><div>We present an integrated multimodal imaging system combining optical-resolution photoacoustic microscopy (OR-PAM) and fluorescence microscopy for quantitative mapping of optical absorption coefficients (<span><math><msub><mi>μ</mi><mi>a</mi></msub></math></span>) in biological tissues. Our platform synergistically merges the molecular specificity of fluorescence imaging with OR-PAM’s depth-resolved quantitative capabilities, enabling precise lesion localization and physiological monitoring. Our system features a novel reconstruction algorithm that integrates Monte Carlo light transport simulations with custom OR-PAM, enabling absolute <span><math><msub><mi>μ</mi><mi>a</mi></msub></math></span> determination − a capability unattainable with fluorescence microscopy and distinct from conventional OR-PAM approaches. The simulation experiment measured the optical absorption coefficient of blood vessels at 532 nm as 238 cm^–1, showing a 3.4 % deviation from the theoretical value of 230.5 cm^–1 (data sourced from the MCML software package). Experimental validation across three model systems demonstrated its diagnostic potential: (1) inflammatory monitoring revealed a 7.9 % <span><math><msub><mi>μ</mi><mi>a</mi></msub></math></span> increase at infection sites (258 vs. 239 cm^–1 in normal vasculature, p &lt; 0.001) within 12 h; (2) tumor tracking showed 5.5 % higher <span><math><msub><mi>μ</mi><mi>a</mi></msub></math></span> in tumor vasculature (252 vs. 237 cm^–1); and (3) cerebral vascular imaging achieved <span><math><msub><mi>μ</mi><mi>a</mi></msub></math></span> quantification (235 cm^–1) following blood–brain barrier opening. These results establish that fluorescence microscopy provides exceptional molecular tracking capability, while OR-PAM delivers quantitative <span><math><msub><mi>μ</mi><mi>a</mi></msub></math></span> differences critical for distinguishing pathological tissues, offering a powerful tool for both fundamental research and clinical diagnostics.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113940"},"PeriodicalIF":5.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219879","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":"Dual matched filter for FMCW lidar: Enabling better range and velocity measurements","authors":"Peng Zhang ,&nbsp;Minghua Chen","doi":"10.1016/j.optlastec.2025.114006","DOIUrl":"10.1016/j.optlastec.2025.114006","url":null,"abstract":"<div><div>Frequency modulated continuous wave lidar, as an important tool to measure velocity and distance, has shown promising prospects in many applications. To address the shortcomings of conventional signal processing methods applied to this type of lidar, a dual matched filter method is proposed in this article. One matched filter is used to derive the velocity of moving target by analyzing the range difference over distinct time intervals, the other one is employed for range measurement by processing the local reference and down-coverted reflected signal. The theoretical analysis demonstrates that the proposed method offers significant advantages over conventional method. Firstly, it doubles the distance measurement range, effectively addressing the inherent range limitations of traditional method. Secondly, it overcomes the critical challenge of close-range high-speed measurement, which remains a persistent drawback in conventional systems. Furthermore, the method maintains distance and velocity measurement precision and resolution at levels comparable to or better than those of traditional method. Crucially, the proposed method achieves a 9.5 dB improvement in signal-to-noise ratio. Additionally, under nonlinear frequency modulation errors of 19.8 MHz, 198 MHz, and 396 MHz, the proposed method consistently delivers superior spectral resolution compared to the conventional method. This study can provide technical guidance and new ideas for researchers in this field.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 114006"},"PeriodicalIF":5.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219876","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":"A novel real-time monitoring approach for surface integrity in laser shock peening: spectro-acoustic data fusion","authors":"Guangyuan Shi ,&nbsp;Haoyu Guan ,&nbsp;Yuanbin Wang ,&nbsp;Nan Ma ,&nbsp;Minchao Cui ,&nbsp;Ming Luo","doi":"10.1016/j.optlastec.2025.113990","DOIUrl":"10.1016/j.optlastec.2025.113990","url":null,"abstract":"<div><div>A spectro-acoustic data fusion approach was employed for real-time monitoring of surface integrity during the laser shock peening (LSP) process, revealing the mechanism of plasma physical field interaction. The apparent plasma temperature and electron density were quantified through spectral analysis, while the propagation behavior of the shock wave was analyzed using the time–frequency characteristics of the airborne acoustic signal. A multivariate regression model was developed using the spectral intensity ratio of Hα/N II 500.515 nm and the peak-to-peak amplitude of the acoustic wave. This model achieved high-precision prediction of surface residual stress (<em>R²</em> = 0.944) and Vickers hardness (<em>R²</em> = 0.946) for γ-TiAl alloy, improving by over 5 % compared to single-signal regression models. A spectro-acoustic fusion diagnostic model incorporating a cross-modal attention mechanism within the Transformer architecture was established, achieving a prediction accuracy of 99.52 %. This study provides significant theoretical and practical contributions to the adaptive LSP of critical aerospace components.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113990"},"PeriodicalIF":5.0,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219877","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":"An agent graph-attention–enhanced transformer for semi-supervised hyperspectral image classification","authors":"Mingmei Zhang ,&nbsp;Jiajie Wang ,&nbsp;Yongan Xue ,&nbsp;Jinling Zhao","doi":"10.1016/j.optlastec.2025.114009","DOIUrl":"10.1016/j.optlastec.2025.114009","url":null,"abstract":"<div><div>Hyperspectral image classification (HSIC) is a key topic in remote sensing research, but acquiring a sufficient quantity of high-quality labeled samples is costly and, in some cases, unattainable. We propose a Semi-Supervised classification network that integrates Agent Graph Attention with a Transformer (AGAT-SS) to fully exploit both labelled and unlabelled samples to improve HSIC performance. The network is composed of three core components: a Feature Alignment Module (FAM), an Agent Graph Attention Network (A-GAT), and an Agent-Enhanced Feed-forward Transformer (AEF-Transformer). FAM employs channel attention and multi-scale convolutions with the objective of enhancing the consistency between labelled and unlabelled data. This process establishes a reliable foundation for subsequent feature extraction. A-GAT introduces an agent-attention mechanism that jointly captures global and local features while markedly reducing computational complexity, yielding efficient and robust feature learning. AEF-Transformer combines Agent Attention with an Enhanced Feed-forward Module (AEFM), thereby substantially strengthening feature-extraction capacity and model expressiveness. Extensive experiments on the public Indian Pines (IP), Pavia University (PU) and Houston 2013 (HU13) datasets indicate that AGAT-SS significantly outperforms excellent algorithms such as Multiscale Dynamic Graph Convolutional Network (MDGCN), Multiscale Spectral–Spatial GAT (MSSGAT), and Dynamic Evolution GAT (DEGAT). In particular, on the IP dataset, when only 5 % of the labeled samples and 20 % of the unlabeled samples were used for training, AGAT-SS outperformed DEGAT by 1.16 % in Overall Accuracy (OA), 1.36 % in Average Accuracy (AA), and 0.91 % in Kappa coefficient. These gains further confirm its superiority in semi-supervised learning.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 114009"},"PeriodicalIF":5.0,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219307","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":"High-Power Low-Divergence 852 nm single transverse mode diode laser with coupled waveguide","authors":"Yongle Zhan ,&nbsp;Qiong Qi ,&nbsp;Cong Xiong ,&nbsp;Shuang Hao ,&nbsp;Lingni Zhu ,&nbsp;Suo Feng ,&nbsp;Suping Liu ,&nbsp;Xiaoyu Ma","doi":"10.1016/j.optlastec.2025.114005","DOIUrl":"10.1016/j.optlastec.2025.114005","url":null,"abstract":"<div><div>By introducing the structure of a coupled large optical cavity (CLOC) and optimizing the position and thickness of the coupled waveguide layer, a high-power single mode semiconductor laser operating at 852 nm with a ridge width of 5 μm was fabricated. Compared to lasers with a conventional optical cavity (OC) structure, the vertical divergence angle of the CLOC structure was reduced from 37.5° to 19.2°. Meanwhile, due to its low internal loss of 0.32 cm^-1 and high modal gain coefficient of 14.3 cm⁻¹, the slope efficiency of the CLOC structure device under room-temperature continuous-wave operation reached 1.15 W/A. The most significant advantage of the CLOC structure lies in the combination of the widened N-side waveguide layer and the inserted coupled waveguide layer, which enables a maximum fundamental mode output power of 760.8 mW—a remarkable improvement compared to the 395.1 mW maximum fundamental mode output power of the OC structure.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 114005"},"PeriodicalIF":5.0,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219309","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":"Extended-range high-accuracy wavelength calibration beyond gas absorption lines using Mach–Zehnder interferometer and Fabry–Pérot cavity","authors":"Yuqi Yu,&nbsp;Junkang Guo,&nbsp;Weijin Meng,&nbsp;Hu Peng,&nbsp;Zhigang Liu","doi":"10.1016/j.optlastec.2025.113993","DOIUrl":"10.1016/j.optlastec.2025.113993","url":null,"abstract":"<div><div>The real-time wavelength calibration of a tunable laser (TL) typically relies on a combination of gas absorption lines and auxiliary interferometers. However, owing to the limited spectral coverage of gas absorption lines, the calibration accuracy deteriorates in regions outside their coverage. To address this limitation, this study proposed a relative wavelength calibration method that integrated a Mach–Zehnder interferometer (MZI) with a Fabry–Pérot (FP) cavity. In this method, the transmission peaks of the FP cavity were used to extend the absolute wavelength reference provided by the gas absorption lines over a broader spectral range. Simultaneously, the stable free spectral range of the FP cavity was utilized to correct the nonlinear phase-frequency mapping in the MZI caused by material dispersion. Furthermore, a complex Morlet wavelet transform was employed to extract the instantaneous phase of the MZI signal with high precision, thereby enhancing the accuracy of the relative calibration. The experimental results demonstrated that the absolute wavelength uncertainty was maintained below 0.4 pm over the extended 40 nm spectral range. For a frequency difference of 40 MHz, the corresponding relative wavelength measurement error was less than 0.5 MHz (approximately 4 fm at 1550 nm). This study provides an effective solution for high-precision wavelength calibration of TL over extended spectral ranges, demonstrating its strong practical value and promising prospects for broad applications.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113993"},"PeriodicalIF":5.0,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219873","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":"DM-YOLO for MLCCs’ automatic defect detection","authors":"Meiyun Chen ,&nbsp;Jiacheng Tian ,&nbsp;Xiuhua Cao ,&nbsp;Zhenxiao Fu ,&nbsp;Dawei Zhang","doi":"10.1016/j.optlastec.2025.113977","DOIUrl":"10.1016/j.optlastec.2025.113977","url":null,"abstract":"<div><div>Defect detection for multi-layer ceramic capacitors (MLCC) is crucial. MLCCs’ defects are characterized by multi-scale and long-tailed distribution. In order to more accurately locate and identify defects in MLCC, this work developed an automatic sampling and sorting device for MLCC, which is characterized by a high level of automation and high-definition sampling of microelectronic components. Then, proposing a Deep Learning based model DM-YOLO (Decouple-trained multiscale-boosted YOLO) for defect detection. In this method, Decoupled Training is exerted on the model’s Detection head for improving its performance from long-tailed effect. For multi-scale targets detection, this model uses the Efficient Implementation of Universal Inverted Bottleneck in Layer-aggregation Network (EULN) module designed in this work, which provides flexible receptive field as needed. Besides, Bi-RepGFPN is used to enhance the feature fusion effect among feature maps from different scales and repair the loss of image characteristic information caused by the network’s increasing depth. The experiments demonstrate that our model achieves an mAP0.5 of 0.942 and an mAP0.5:0.95 of 0.615 on the MLCCs’ dataset. And the recall rate of DM-YOLO on this dataset achieves 0.925, meeting the requirements for the task of MLCCs’ defect detection.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113977"},"PeriodicalIF":5.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157727","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":"Hyperspectral image classification using local-to-global retention network","authors":"Rajat Kumar Arya,&nbsp;Subhojit Paul,&nbsp;Rajeev Srivastava","doi":"10.1016/j.optlastec.2025.113991","DOIUrl":"10.1016/j.optlastec.2025.113991","url":null,"abstract":"<div><div>Several transformer-based methods have demonstrated competitiveness in the hyperspectral image (HSI) classification tasks. However, the transformer has an expensive and slow inference due to the computational complexity of the self-attention mechanism, which increases the risk of a bottleneck while processing all the tokens for high-resolution images. Retentive Network (RetNet) has recently been proposed for large language models to achieve training parallelism, low-cost inference, and high performance. However, RetNet also struggles to capture local information, such as conventional transformers. This study proposes local-to-global retention (LGRetention) to overcome the issues. The proposed method directly obtains the inherent features from the original spatial-spectral patch, thereby preserving the spatial distribution and intrinsic spectral-spatial correlation. Moreover, the proposed LGRetention includes a local-to-global self-retention (LGSR), which contains Local Convolutional Network (LCN) and Global Self-Retention (GSR) modules created using three-dimensional (3D) convolutional neural networks (CNNs) and a developed HSI Retention mechanism to capture local and global features and enhance the long-range dependencies and spectral-spatial feature learning ability, thereby capturing both fine and coarse-grained data. In the HSI Retention mechanism, we developed a 3D parallel retention mechanism to retain the degradation between succeeding horizontal and vertical positions with the spectral dimension of the HSI data. Experimental results on three benchmark HSI datasets demonstrate that the proposed LGRetention outperforms the state-of-the-art methods. It increases accuracy and creates finer classification maps, demonstrating robustness and generalizability in the HSI classification task.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113991"},"PeriodicalIF":5.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157728","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":"A dual - mode refractive index sensor based on multilayer gold nanodisk - intercalated UCNP heterogeneous metamaterial","authors":"Zihong Li ,&nbsp;Shengbin Cheng ,&nbsp;Xiaofeng Wu ,&nbsp;Maolin Wen ,&nbsp;Shiping Zhan","doi":"10.1016/j.optlastec.2025.113936","DOIUrl":"10.1016/j.optlastec.2025.113936","url":null,"abstract":"<div><div>High-precision refractive index sensors are pivotal for medical diagnostics, environmental monitoring, and bioanalysis. This study presents a dual-mode refractive index sensor integrating spectral shift detection and fluorescence enhancement through a gold nanodisk-UCNP heterogeneous metamaterial. By optimizing structural parameters (e.g., metal layer number, nanodisk radius), tunable multiplexed band absorption is achieved. The platform exhibits strong local field amplification at 808, 980, 1064, and 1550 nm wavelengths, significantly boosting UCNP optical signals while accommodating diverse sensitizer doping configurations. Beyond conventional refractive-index-induced spectral shifts, a linear correlation between local field strength and refractive index is revealed, enabling a dual-mode mechanism that concurrently links spectral shifts and luminescence intensity to refractive index variations. Demonstrating broad compatibility with UCNP with different dopant ions, this design advances sensing technology through synergistic spectral-intensity modulation, with applications spanning diabetes detection, tunable nanolight sources, and high-sensitivity environmental monitoring systems.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113936"},"PeriodicalIF":5.0,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157735","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}