Optics and Laser Technology最新文献

{"title":"Color image blind watermarking algorithm based on the feature of energy concentration","authors":"Yunfei Qiu ,&nbsp;Shuai Jiao ,&nbsp;Xiaodong Chen ,&nbsp;Lin Su ,&nbsp;Xuefeng Wei ,&nbsp;Qingtang Su","doi":"10.1016/j.optlastec.2025.113472","DOIUrl":"10.1016/j.optlastec.2025.113472","url":null,"abstract":"<div><div>With the growing prevalence of digital images, ensuring their security and resolving copyright disputes have become critical challenges. According to the feature of image energy concentration, a novel blind watermarking method for color images, using discrete cosine transform (DCT), Laplace transform (LT), and the water cycle algorithm (WCA), is proposed in this paper. The watermark image is scrambled to generate a binary sequence by a two-dimensional logistic adjusted sine map (2D-LASM). The colour host image undergoes dimensionally reduction, 4 × 4 block division, and DCT. A 2 × 2 low-frequency coefficient block is selected, and its energy is aggregated using Laplace transform. Watermark embedding is achieved via quantization index modulation on the highest energy coefficients. WCA optimizes the embedding step size to balance robustness and invisibility, while geometric correction enhances resilience against attacks. Experimental results indicate that the proposed scheme has excellent invisibility (PSNR≈42 <em>dB</em>, SSIM≈0.97) and strong robustness (NC≈0.95). Additionally, the scheme achieves an embedding capacity of 0.03125 bpp and excellent security, setting a new benchmark for colour image watermarking solutions.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113472"},"PeriodicalIF":4.6,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523409","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":"Spatiotemporal tracking of rotational dynamics of erythrocytes using AI-assisted digital in-line holographic microscopy","authors":"Jihwan Kim ,&nbsp;Youngdo Kim ,&nbsp;Kyler J. Howard ,&nbsp;Sang Joon Lee","doi":"10.1016/j.optlastec.2025.113418","DOIUrl":"10.1016/j.optlastec.2025.113418","url":null,"abstract":"<div><div>Conventional digital in-line holographic microscopy (DIHM) has technical limitations in measuring depth-wise positional and orientational information of biconcave red blood cells (RBCs). Here, we propose a non-invasive image-based methodology for analyzing translational and rotational dynamics of erythrocytes by integrating artificial intelligence (AI) and DIHM technologies. Hologram datasets consist of in-focus holographic images and out-of-plane angle labels of tumbling RBCs in a viscoelastic fluid flow. The similarity in rotational behaviors of tumbling RBCs and ellipsoids is experimentally verified. The hologram datasets are utilized to determine the depth-wise locations of RBCs by using a structural similarity index measure focus function and to train a deep learning network for orientation measurement. The proposed AI-assisted DIHM technique for measuring three-dimensional positions and orientations of RBCs is applied to analyze their temporal variations in translational and rotational behaviors in a sudden expansion pipe, which is difficult to measure with conventional measurement techniques. This AI-assisted DIHM technique would be effectively utilized to diagnose various dynamic behaviors of abnormal RBCs associated with hematologic diseases in microfluidic devices inspired by human blood vessels.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113418"},"PeriodicalIF":4.6,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523410","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 mode-locked fiber laser based on Sb2Se3 SA with switchable single, dual wavelength pulses and multi-frequencies NLSPs","authors":"Xingwei Li ,&nbsp;Yanjun Zhang ,&nbsp;Huijing Du ,&nbsp;Peng Wang ,&nbsp;Geng Li ,&nbsp;Meng Li ,&nbsp;Ling Qin ,&nbsp;Jiaxin Zhang ,&nbsp;Yubin Zhang ,&nbsp;Menglei Pei ,&nbsp;Shuguang Li ,&nbsp;Jianshe Li","doi":"10.1016/j.optlastec.2025.113492","DOIUrl":"10.1016/j.optlastec.2025.113492","url":null,"abstract":"<div><div>Sb₂Se₃ is an ideal optoelectronic material, which can be used in optoelectronic fields such as optical modulators and fiber lasers. In this paper, Sb₂Se₃ saturable absorber is made by tapered fiber. The measured results reflect that it has good nonlinear characteristics, and the modulation depth is 5.8%. A fiber laser based on tapered fiber Sb₂Se₃ saturable absorber is constructed, achieving single and dual wavelength tunability, switching between soliton pulses and multi-frequencies noise like square pulses. Due to mode competition, we find the number of frequencies in the resonator increases first and then decreases with the increase of pump power. Sb₂Se₃ opens up new avenues for exploring ultra-short pulse sources with varied pulse types and dual wavelengths, highlighting its potential for nonlinear optical materials and ultrafast pulse generation.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113492"},"PeriodicalIF":4.6,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523411","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":"Gallium nitride: a strong candidate to replace GaAs as base material for optical photovoltaic converters in space exploration","authors":"Javier F. Lozano ,&nbsp;Natalia Seoane ,&nbsp;J.M. Guedes ,&nbsp;Enrique Comesaña ,&nbsp;Julian G. Fernandez ,&nbsp;Florencia M. Almonacid ,&nbsp;Eduardo F. Fernández ,&nbsp;Antonio García-Loureiro","doi":"10.1016/j.optlastec.2025.113447","DOIUrl":"10.1016/j.optlastec.2025.113447","url":null,"abstract":"<div><div>High power laser transmission technology is expected to play an important role in spatial exploration. To increase the amount of power delivered, some issues must be addressed. Currently, optical photovoltaic converters are based on GaAs, a material with a bandgap energy of 1.42 eV. In this work we propose gallium nitride (GaN) as base material for optical photovoltaic converters due to its high bandgap (3.39 eV), which reduces both ohmic and intrinsic entropic losses, and its high thermal conductivity and resistance to radiation damage, making it suitable for space applications. We have optimized several GaN optical photovoltaic converter devices under a wide range of laser power densities and temperatures. The resilience to variations in the design parameters is also tested. Results show that, due to their large bandgap energy, GaN devices could suffer from fewer performance losses with the temperature when compared to other materials with lower bandgaps. The devices show great tolerance to variations in the P layer (bottom layer), while the N layer thickness and doping concentration must be carefully manufactured. When compared to GaAs-based devices, GaN shows higher efficiency across the entire laser power density range, achieving efficiencies near 80 % and surpassing the current state-of-the-art power converter by <span><math><mo>≈</mo></math></span>10 % at 10 <span><math><mtext>W</mtext><mspace></mspace><msup><mtext>cm</mtext><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span>. The proposed GaN devices show a peak of performance at a laser power density as high as 100 <span><math><mtext>W</mtext><mspace></mspace><msup><mtext>cm</mtext><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span>. Although manufacturing issues could degrade the efficiency of GaN power converters, this results position GaN as a promising material for a new generation of ultra-high efficient optical photovoltaic converters.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113447"},"PeriodicalIF":4.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523391","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":"Study of convexity on nanosecond laser-induced damage growth in fused silica","authors":"Jiajie Miao,&nbsp;Chengyu Zhu,&nbsp;Hasi Wuliji,&nbsp;Jincheng Niu,&nbsp;Shenghao Kang,&nbsp;Ziqiang Dan,&nbsp;Liang Shao,&nbsp;Jiajun Nie,&nbsp;Hang Yuan","doi":"10.1016/j.optlastec.2025.113478","DOIUrl":"10.1016/j.optlastec.2025.113478","url":null,"abstract":"<div><div>Damage growth in fused silica under ultraviolet nanosecond laser irradiation poses a significant threat to the stable operation of high-power laser systems and shortens the service life of optical components. In this study, an experimental scheme was developed in which initial damage sites were deliberately fabricated and subsequently subjected to medium-aperture laser irradiation to induce further growth. A time-resolved shadowgraph imaging system was designed to capture the dynamic evolution of damage morphology and polarization characteristics. Statistical analysis of the final damage images—acquired from both transmission-view and side-view microscopic imaging systems—revealed that the damage morphology, particularly the structure of radial cracks, plays a key role in determining the damage growth coefficient. To quantitatively characterize the morphology of radial cracks, a novel morphological parameter, convexity, was introduced. The analysis showed that damage sites with lower convexity generally exhibited higher growth coefficients and shallower damage depths. These findings provide valuable theoretical insights for the prediction and mitigation of laser-induced damage and establish a foundation for the further refinement of damage growth models.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113478"},"PeriodicalIF":4.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523408","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":"Design of long-wave infrared coded aperture imaging optical system and polarization aberration analysis based on vector diffraction characteristics","authors":"Chao Wang ,&nbsp;Wenchao Yu ,&nbsp;Yingchao Li","doi":"10.1016/j.optlastec.2025.113468","DOIUrl":"10.1016/j.optlastec.2025.113468","url":null,"abstract":"<div><div>To address the issue where diffraction phenomena in long-wave infrared (LWIR) polarization optical systems containing a digital micromirror device (DMD) induce variations in polarization aberrations, thereby degrading polarization measurement accuracy, we propose a polarization aberration analysis and compensation method for LWIR secondary imaging optical systems incorporating DMD. The method effectively mitigates the impact of diffraction on polarization aberrations. Simulation results indicate that the modulation transfer function (MTF) across the whole field of view approaches the diffraction limit at the cutoff frequency, with maximum distortion below 0.2%. The imaging quality remains excellent, while the diattenuation and retardance of the system are reduced to 0.08 times and 0.74 times of their original values, respectively. Experimental measurements confirm polarization aberration errors below 5%, with polarization preservation performance ranging from 92.06% to 95.01%. The system achieves diffraction-limited performance. The proposed analytical model elucidates the relationship between diffraction and polarization aberrations, and the compensation method significantly reduces polarization aberrations.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113468"},"PeriodicalIF":4.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518391","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":"ECO-SWGST: ECO-based tracking with side window generalized structure tensor for real-time infrared small target tracking","authors":"Zhe Wang ,&nbsp;Jiaxing Wang ,&nbsp;Yiran Wang ,&nbsp;Bin Gao ,&nbsp;Zhengjun Liu ,&nbsp;Shutian Liu ,&nbsp;Yutong Li","doi":"10.1016/j.optlastec.2025.113470","DOIUrl":"10.1016/j.optlastec.2025.113470","url":null,"abstract":"<div><div>Infrared small target tracking is a crucial research direction in infrared search and track systems, and enhancing detection and tracking accuracy in complex backgrounds while meeting real-time requirements remains a challenging task. To enhance the performance of traditional correlation filter algorithms, we propose a side window generalized structure tensor (SWGST) detection framework for real-time infrared small target tracking. The proposed method is built upon the correlation filter framework efficient convolution operators (ECO) and integrates SWGST. SWGST uses an anisotropic neighborhood selection strategy and incorporates eight-direction window filtering during the computation of the generalized structure tensor. Extensive experiments demonstrate that the proposed model successfully combines the detection algorithm with the correlation filter tracking framework, significantly improving the accuracy and effectiveness of real-time tracking. This approach enhances the certainty map of small targets, significantly improving the discrimination between targets and background edges while maintaining computational efficiency.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113470"},"PeriodicalIF":4.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523390","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":"Applications of complex surfaces in ophthalmic lens design: microlens arrays, freeform surfaces, and diffractive optics","authors":"Chongxing Liu,&nbsp;Ying Yang,&nbsp;Wanting Yang,&nbsp;Bo Dong,&nbsp;Changxi Xue","doi":"10.1016/j.optlastec.2025.113471","DOIUrl":"10.1016/j.optlastec.2025.113471","url":null,"abstract":"<div><div>Complex surface technologies, including microlens arrays, freeform surfaces, and diffractive optics, are employed in ophthalmic lenses to improve visual acuity and optical quality. These surfaces have revolutionized the way we achieve vision correction and enhance optical performance. With the continuous advancement of technology, significant progress has been made in optical design within the field of ophthalmic lenses. In this review, we focus on the basic principles, the development status of innovative technologies, and diverse applications of these complex surface optical systems in ophthalmic lenses. We review the advantages and disadvantages of applying microlens arrays, freeform surfaces, and diffractive designs in ophthalmic lenses. These analyses help researchers select the best surface design for different ophthalmic lenses, leading to the generation of more designs with excellent optical performance. Moreover, we delve into the challenges and constraints encountered in the practical application of these technologies and offer insights into the future research directions and development trends in the field of ophthalmic lenses.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113471"},"PeriodicalIF":4.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523997","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":"Challenges of optical manufacturing techniques applied in improving the laser damage resistance of hard-brittle fused silica optics","authors":"Jian Cheng ,&nbsp;Guang Chen ,&nbsp;Mingjun Chen ,&nbsp;Linjie Zhao ,&nbsp;Qiao Xu ,&nbsp;Xiaodong Yuan ,&nbsp;Zhichao Liu ,&nbsp;Shengfei Wang ,&nbsp;Wei Liao ,&nbsp;Qi Liu ,&nbsp;Wenyu Ding","doi":"10.1016/j.optlastec.2025.113475","DOIUrl":"10.1016/j.optlastec.2025.113475","url":null,"abstract":"<div><div>Fused silica optics (e.g., wedged focus lenses, continuous phase plate) with high-performance and accuracy are key components in laser-driven inertial confinement fusion (LD-ICF) facilities which deliver megajoule and petawatt lasers for fusion ignition. The LD-ICF necessitates the use of high-quality, large-aperture fused silica optics to control laser beams temporally, spatially, and spectrally, posing significant ultra-precision manufacturing challenges. When these fused silica optics are exposed to intense laser pulses, laser-induced surface damage (LISD) might generate and then escalate rapidly during subsequent laser shots. This has been a limiting factor in the promotion of output energy in LD-ICF. The root cause of LISD is surface/subsurface defects (SSD). Therefore, eradicating SSD is essential to reduce LISD initiations and repair them. In response to this issue, various techniques have been developed to enhance the laser damage resistance (LDR) of fused silica optics by inhibiting SSD and repairing LISD. Nevertheless, the actual LDR of these optics in practical applications is still significantly below the intrinsic thresholds of their raw materials. A comprehensive and in-depth review of LDR improvement techniques is necessary to provide references for manufacturing high-performance fused silica optics. This paper summarizes the development of cutting-edge manufacturing techniques used to enhance the LDR of fused silica optics. These techniques might introduce new damage precursors (such as redepositions and chemical structure defects), constraining further enhancements in the LDR of fused silica optics. These challenges and their solutions are discussed and analyzed emphatically, and the future trends of LDR improvement techniques are explored. This study aims to provide a foundation and guidance for manufacturing high-performance fused silica optics as well as other hard-brittle optics, thereby propelling the advancement of LD-ICF.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113475"},"PeriodicalIF":4.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518393","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":"Study on laser ablation of TC4 for drag reduction groove considering plasma shielding effect","authors":"Li Zhang ,&nbsp;Tianci Wu ,&nbsp;Yunfei Luo ,&nbsp;Jingyuan Xu ,&nbsp;Jinghan Liu ,&nbsp;Lulin Zhang","doi":"10.1016/j.optlastec.2025.113467","DOIUrl":"10.1016/j.optlastec.2025.113467","url":null,"abstract":"<div><div>Inspired by the structure of shark skin, rib grooves have demonstrated significant potential for drag reduction in applications such as aviation and pipeline transportation. Laser ablation, owing to its high efficiency and cost-effectiveness, when combined with numerical simulations, enables precise control over the groove structure to optimize drag reduction performance. This research develops a predictive model for laser ablation that incorporates the plasma shielding effect, systematically investigating the evolution of surface morphology during the laser ablation of TC4 titanium alloy. The influence of varying laser parameters on groove morphology is analyzed, with the model’s accuracy rigorously validated against experimental data. Building on this foundation, the study further employs the simulation model to establish a quantitative relationship between groove morphology and drag reduction performance. By adjusting laser parameters, the model facilitates rapid and accurate simulation and prediction of optimal groove dimensions for maximum drag reduction, thereby guiding the fabrication of drag-reducing specimens. Experimental results reveal that, in closed-channel tests, the optimal drag reduction is achieved when the groove depth-to-spacing ratio is 0.5, yielding a maximum drag reduction rate of 11.3%. The numerical simulations presented in this study serve as a valuable tool for optimizing laser parameters and predicting the drag reduction capabilities of functional surfaces.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113467"},"PeriodicalIF":4.6,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518386","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}