Li Zhang , Tianci Wu , Yunfei Luo , Jingyuan Xu , Jinghan Liu , Lulin Zhang
{"title":"Study on laser ablation of TC4 for drag reduction groove considering plasma shielding effect","authors":"Li Zhang , Tianci Wu , Yunfei Luo , Jingyuan Xu , Jinghan Liu , 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}
{"title":"Characterisation of CFRP surface and internal defects detection based on line laser scanning thermography","authors":"Haoze Chen , Zhijie Zhang , Wuliang Yin , Zong Meng","doi":"10.1016/j.optlastec.2025.113473","DOIUrl":"10.1016/j.optlastec.2025.113473","url":null,"abstract":"<div><div>Defects in carbon fiber reinforced polymers can lead to serious structural safety issues. In order to effectively detect surface and internal defects, this paper proposes a laser-based line-scanning thermography nondestructive testing system and an unsupervised edge detection method based on principal component analysis combined with K-mean clustering. A total of 30 typical defects, including matrix cracks of different sizes, impact damage and internal delamination defects, were prepared and tested to evaluate the feasibility of the proposed method. The experimental results show that the change detection method can achieve accurate shape characterization for different kinds of typical defects. Accurate identification of 98.8% of the burial depth of delamination defects can be achieved by support vector machines. The outcomes of this study can be used as a possible method for evaluating typical defects in CFRP.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113473"},"PeriodicalIF":4.6,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144513543","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}
Junlei Shi , Lansong Yang , Hao Zhou, Peixin Fu, Pingjun Tao, Yuanzheng Yang
{"title":"Effects of laser cutting on microstructure, hardness and magnetic properties of Fe-based amorphous ribbons","authors":"Junlei Shi , Lansong Yang , Hao Zhou, Peixin Fu, Pingjun Tao, Yuanzheng Yang","doi":"10.1016/j.optlastec.2025.113479","DOIUrl":"10.1016/j.optlastec.2025.113479","url":null,"abstract":"<div><div>Fe-based amorphous alloys are extensively utilized in electromagnetic components owing to their outstanding mechanical and magnetic properties, holding significant potential in solid-state transformers and amorphous motors. However, the deterioration of magnetic properties after processing has hindered the applications of these alloys. Traditional processing methods can induce deformation near the cutting edge and significant crystallization, severely degrading the magnetic property. In contrast, the laser cutting method offers minimal heat effects, a non-contact approach, and low magnetic property deterioration, making it as the optimal technique for cutting Fe-based amorphous alloys. In this research, a continuous-wave infrared laser cutting technique is employed to cut the amorphous ribbons into a ring shape at different laser powers and laminated magnetic cores should be prepared. The results reveal the presence of three distinct zones from the cutting edge to the substrate, namely the melted zone, heat affected zone and basis zone. Notably, Only the α-Fe(Si) phase is formed in the crystallization zone due to the relatively short duration of the laser cutting process for the amorphous ribbon and average grain sizes gradually decreases from the cutting edge to the basis zone. Furthermore, the amorphous-nanocrystalline dual-phase resulting from laser cutting exhibits a high hardness of approximately 1035 HV at 20 μm from the cut edge. Additionally, the laser-cut laminated cores at a power of 75 W exhibit excellent combined properties, including width of the crystallization zone of 80 μm and a low loss of 53.96 W/kg (200 mT, 100 kHz). This research offers a theoretical foundation for the industrialization of solid-state transformers and amorphous motors.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113479"},"PeriodicalIF":4.6,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518390","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":"Control of surface relief grating profiles in azopolymer thin films using polarization projection lithography","authors":"A.P. Porfirev , S.N. Khonina , V.V. Popov , M.A. Bugakov , N.I. Boiko , N.A. Ivliev , D.P. Porfirev","doi":"10.1016/j.optlastec.2025.113477","DOIUrl":"10.1016/j.optlastec.2025.113477","url":null,"abstract":"<div><div>The redistribution of azobenzene molecules under the illumination of structurally polarized light is a way for the formation of desired nano- and micro-reliefs. The control of polarization distribution, achieved through conventional spatial light modulators (SLMs), enables the implementation of polarization lithography setups for precise dynamic control of relief formation in thin films of these materials. In this study, we present a polarization projection lithography setup based on a transmissive SLM for the fabrication of surface relief gratings (SRGs) with controlled profiles of a single period in azopolymer thin films. To control the profiles of the fabricated SRGs, we utilize periodically modulated polarization distributions implemented using various designed masks displayed on the SLM. The proposed approach allows us to manipulate the parameters of the fabricated SRGs, such as amplitude and period, by adjusting the level of polarization modulation and the period of this modulation. By employing different mask gratings displayed on the SLM, we fabricate several types of SRGs that redistribute the energy of the incident radiation among the shaped diffraction orders in specific ways, in contrast to conventional sinusoidal SRGs. This demonstrates the unique capabilities of the proposed SLM-based approach for the fabrication of complex microelements and three-dimensional microstructures.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113477"},"PeriodicalIF":4.6,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144513540","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}
Chang Cui , Tongxin Wang , Huakai Mao , Mengzhao Li , Long Huang , Zhen Lin , Senao Gao , Bing Yang , Guodong Zhang
{"title":"Surface morphology and properties of structural steel via laser cleaning with saline solution pretreatment","authors":"Chang Cui , Tongxin Wang , Huakai Mao , Mengzhao Li , Long Huang , Zhen Lin , Senao Gao , Bing Yang , Guodong Zhang","doi":"10.1016/j.optlastec.2025.113435","DOIUrl":"10.1016/j.optlastec.2025.113435","url":null,"abstract":"<div><div>As a novel green cleaning technology, laser cleaning has garnered significant attention. However, its efficacy may be limited for steel structures with deep rust layers formed under prolonged natural environmental exposure. To address this challenge, this study systematically compares the performance of dry laser cleaning, wet laser cleaning and saline solution-laser composite cleaning for rust removal on Q235 structural steel, focusing on surface morphology, roughness, hardness, and microstructural evolution. Results demonstrate that acidic saline solution-laser composite cleaning achieves optimal performance at a pulse frequency of 80 kHz, a laser power of 80 W and 8 cleaning passes, characterized by minimal residual contaminants (Sa = 3.266 µm, Sq = 5.316 µm), uniform surface profiles, and the highest hardness value (192.14 HV). Mechanistic analysis reveals that the acidic solution dissolves rust layers via acidic reactions while generating cracks/pores to enhance laser energy absorption. Subsequent laser irradiation induces localized high temperatures and pressures, vaporizing residual rust and suppressing secondary oxidation through a retained liquid film. In contrast, alkaline cleaning primarily removes oily contaminants via alkaline saponification but exhibits limited rust dissolution due to insufficient Fe<sup>3+</sup> activation. Dry laser cleaning underperforms due to oxide retention and roughness inhomogeneity. This study proposes a scalable and adaptive rust removal strategy, highlighting the industrial potential of saline solution-laser synergy in complex corrosion scenarios.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113435"},"PeriodicalIF":4.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501674","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}
Taehee Kim , Seonyoung Park , M. Meyyappan , Kihyun Kim
{"title":"Enhancement of whispering-gallery-mode lasing in GaN nanoflower-type microdisk with multiple branches","authors":"Taehee Kim , Seonyoung Park , M. Meyyappan , Kihyun Kim","doi":"10.1016/j.optlastec.2025.113458","DOIUrl":"10.1016/j.optlastec.2025.113458","url":null,"abstract":"<div><div>We fabricate GaN-based flower-type micro-cavity lasers as an alternative to conventional microdisks and analyze their optical characteristics. The optical output intensity of the flower-type lasers is 8 times higher than that of circular microcavity lasers, which is enhanced with increasing number of petals. The emission characteristics indicate stronger emission in edge areas of the device compared to the center region due to the three-dimensional whispering gallery mode. The nano-flower devices exhibit a very low threshold current of 50 µA, which is much smaller than that of the circular counterpart. The emission modes of the flower-type lasers are in excellent agreement with a three-dimensional Rayleigh-Fabry-Pérot model. The fabrication of the petal design involves only one additional etching step, resulting in significantly higher performance. The results show that the nano-flower structure can provide enhanced performance in photonics applications relative to the conventional disk-type lasers.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113458"},"PeriodicalIF":4.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501679","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}
Zehou Li , Jun Wang , Liangzheng Ji , Jing Zhang , Yang Liu
{"title":"A case study: dynamic behavior of a typical Micro-LED chips during laser induced forward transfer process","authors":"Zehou Li , Jun Wang , Liangzheng Ji , Jing Zhang , Yang Liu","doi":"10.1016/j.optlastec.2025.113411","DOIUrl":"10.1016/j.optlastec.2025.113411","url":null,"abstract":"<div><div>In Laser Induced Forward Transfer (LIFT) technology, low transfer yield of micrometer-scale chips, especially with tens of millions, limits Micro-LED large-scale use. Many studies explore LIFT process parameters, but few examine the chip descent process. We analyze this process and find a neglected issue: during LIFT transfer of commercial Micro-LED chips, chips rotate after release from the donor substrate, reducing yield. Our analysis reveals the cause: asymmetric geometry and uneven mass distribution in these chips misalign the geometric center and center of mass, creating torque that drives unavoidable rotation and lowers yield. We propose a fix: adjusting laser fluence and transfer distance, key LIFT parameters, to control chip rotation and improve yield. Tests show slow, manageable rotation at 70mJ/cm<sup>2</sup> fluence and under 100 μm distance. Beyond 100 μm at this fluence, rotation speeds up to 1.2°/μm, raising failure risk. Higher fluence and distance increase rotation, peaking at 2.5°/μm. Optimal parameters for these uneven chips are 70–75mJ laser energy and 80–100 μm transfer distance, achieving industry-standard yields. Our work bridges a gap in prior LIFT process research, explaining why shorter transfer distances improve yield, unresolved in prior studies.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113411"},"PeriodicalIF":4.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501675","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}
Junqi Xue , Yukui Cai , Jawad Aslam , Xiaoliang Liang , Xing Li , Yunqing Tang , Zhanqiang Liu
{"title":"Laser surface texture for enhancement of tribological performance of AISI 5115 steel engine valve train components","authors":"Junqi Xue , Yukui Cai , Jawad Aslam , Xiaoliang Liang , Xing Li , Yunqing Tang , Zhanqiang Liu","doi":"10.1016/j.optlastec.2025.113456","DOIUrl":"10.1016/j.optlastec.2025.113456","url":null,"abstract":"<div><div>Surface texturing is a promising technique for enhancing the tribological properties of contact surfaces. This study investigates the influence of texture geometry, orientation, and density on tribological efficiency under specific operating load and lubrication conditions. To improve the friction and wear properties of AISI 5115 steel, the surface was textured using a femtosecond fiber laser with three different geometries (triangle, ellipse, and circle) and four densities (5 %, 10 %, 15 %, and 20 %) in their correlation to reduce wettability contact angle to make surface super-oleophilic. The tribological performance of the textured surfaces was evaluated in dry, starved, and lubricated conditions at 100 RPM, 200 RPM, and 400 RPM using a pin-on-disc tribometer. Wear morphology and 3D surface roughness were analyzed using scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM). A comparative analysis based on wear and the coefficient of friction (COF) for various geometries and densities was conducted, providing insights into the optimization of surface texturing for enhanced tribological performance. Compared to the untextured surface, 15 % ellipse texture with an aspect ratio of 0.1 incline at an angle of 45° have reduced COF by 18.8 %, 72.2 %, and 72 % for dry, staved, and lubricated conditions respectively. Similarly, 15 % ellipse texture has reduced wear by 93.2 %, 78.9 %, and 55.5 % in dry, starved, and lubricated conditions, respectively, in comparison to the untextured surface.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113456"},"PeriodicalIF":4.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501678","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":"Joint intensity-spectral polarization hierarchical fusion guided efficient transparent object detection","authors":"Xueqiang Fan, Longyu Qiao, Bing Lin, Zhongyi Guo","doi":"10.1016/j.optlastec.2025.113429","DOIUrl":"10.1016/j.optlastec.2025.113429","url":null,"abstract":"<div><div>The field of object detection has emerged as a critical and valuable research frontier. Nevertheless, the detection of transparent objects remains an unresolved and challenging problem, primarily due to their limited texture and color information. Towards being able to address this situation, we propose a novel intensity-spectral polarization fusion framework, termed as FuseISP, specifically designed for transparent object discrimination. FuseISP starts by utilizing hierarchical feature extractor for each feature source, <em>i.e.</em>, trichromatic intensities or trichromatic linear polarization cues, to produce abundant high- and low-frequency features. Subsequently, we implement an intensity-spectral polarization mixed modulator to enhance interactions between intensity and spectral polarization information. Additionally, FuseISP introduces a new hierarchical feature fusion module to establish connections among different levels for modelling the shared information. Lastly, a multi-level decoder module based on the integration of 2D convolutional neural networks (CNNs) and 3D CNNs, which can simultaneously capture inter- and intra-polarization relationships, is designed to construct the transparent object detector in a deeply supervised manner. Experimental results show our proposed method outperforms other advanced approaches in the real-world scenes.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113429"},"PeriodicalIF":4.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144510695","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}
Shi Qiu , Liang Chai , Jinhui Yuan , Bin Liu , Lijiao Zu , Kuiru Wang , Binbin Yan , Xinzhu Sang , Xingdao He , Qiang Wu
{"title":"Highly sensitive hydrogen sensor based on a U-shaped microfiber interferometer coated with Pt/WO3","authors":"Shi Qiu , Liang Chai , Jinhui Yuan , Bin Liu , Lijiao Zu , Kuiru Wang , Binbin Yan , Xinzhu Sang , Xingdao He , Qiang Wu","doi":"10.1016/j.optlastec.2025.113427","DOIUrl":"10.1016/j.optlastec.2025.113427","url":null,"abstract":"<div><div>As the extensive application of hydrogen energy, highly sensitive detection of hydrogen is important to prevent the risk of an explosion. To achieve good sensing stability, (3-Aminopropyl) triethoxysilane (APTES) was used to immobilize Pt/WO<sub>3</sub> on the U-shaped microfiber sensor. The experimental results show that the proposed U-shaped single mode-tapered four core-single mode (STFS) microfiber sensor has good spectrum stability (maximum wavelength perturbation of 0.013 nm over 30 min) and long-term stability (13 days). Furthermore, when the concentration of hydrogen is changed from 0 % to 1 %, the proposed U-shaped STFS microfiber hydrogen sensor shows a high sensitivity of −17.706 nm/% and a good linearity with a linear regression coefficient of 0.996. The developed hydrogen sensor has temperature and RH sensitivities of 0.0114 nm/℃ and 0.006 nm/%RH, respectively, indicating low temperature and RH cross-sensitivity to hydrogen measurement. The proposed U-shaped STFS microfiber sensor and the functionalized method have potential applications in hydrogen detection, prevention of hydrogen-related accidents and other fields.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113427"},"PeriodicalIF":4.6,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144510696","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}