Optics and Laser Technology最新文献

{"title":"Photocontrolled chiral-nematic Fabry-Pérot cavity","authors":"M.N. Krakhalev ,&nbsp;A.S. Abdullaev ,&nbsp;A.S. Zuev ,&nbsp;V.A. Gunyakov ,&nbsp;I.V. Timofeev ,&nbsp;V.Ya. Zyryanov","doi":"10.1016/j.optlastec.2025.113012","DOIUrl":"10.1016/j.optlastec.2025.113012","url":null,"abstract":"<div><div>The spectral and polarisation characteristics of a Fabry–Pérot cavity filled with photo-controlled chiral nematic are investigated. The chiral nematic under planar-tangential boundary conditions is used, enabling the structure to change in the twist angle continuously under the action of the controlling blue or UV light. An increase in the structure twist angle leads to a rise in the geometric phase of the eigenmodes accompanied by a red spectral shift of <span><math><mrow><mi>r</mi><mi>e</mi></mrow></math></span>-modes and a blue spectral shift of <span><math><mrow><mi>r</mi><mi>o</mi></mrow></math></span>-modes. The spectral shift of the modes is studied experimentally, through numerical simulation and by analytical treatment. A generalised resonance diagram of the chiral nematic cavity is obtained. Measurements of the geometric phase values as a function of the structure twist angle are made. The proposed chiral nematic cavity with a variable geometric phase can be promising to develop photonic devices with photo-controlled features.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113012"},"PeriodicalIF":4.6,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912813","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 low-cost wire grid polarizer with an average extinction ratio of 40 dB in SWIR range realized by oblique angled deposition","authors":"Xingwei Liu,&nbsp;Zefan Lin,&nbsp;Zhehao Zhang,&nbsp;Yuwei Chai,&nbsp;Lingxue Wang,&nbsp;Guoguo Kang","doi":"10.1016/j.optlastec.2025.113099","DOIUrl":"10.1016/j.optlastec.2025.113099","url":null,"abstract":"<div><div>Classical metal wire grid polarizers are commonly employed as infrared polarizers due to their broad operating spectrum. However, their low extinction ratio limits applications in high-precision infrared polarization in short-wavelength infrared range. Analysis using the Rigorous Coupled Wave Analysis indicates that the extinction ratio of a metal wire grid polarizer is positively correlated with the depth of the metal grating layer. Traditional etching and lift-off methods are insufficient for achieving the necessary depth to realize a high extinction ratio. In this paper, we propose an approach to fabricate infrared wire grid polarizers with ultra-high extinction ratios by combining Laser Interference Lithography with Oblique Angled Deposition method. The wire grid polarizer has a periodic structure of 300 nm and a grating layer depth of 450 nm, with an aspect ratio of 3:1. Experimental results demonstrate that the average transmission for TM wave exceeds 70 %, while the average extinction ratio surpasses 40 dB (10000:1) within the 1 μm to 2.5 μm range. The wire grid polarizer fabricated using the simple and low-cost methods has the potential to become a commercially viable product.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113099"},"PeriodicalIF":4.6,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912815","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":"Pulse laser ablated gold-titania nanocomposites-sensitized optical fiber sensor: Petroleum detection performance and sensing mechanism","authors":"Manal Alhathal ,&nbsp;A.A. Salim ,&nbsp;Mahmood Alhajj ,&nbsp;S. K. Ghoshal ,&nbsp;Muhammad Safwan ,&nbsp;Ganesan Krishnan ,&nbsp;Sunita Sharma","doi":"10.1016/j.optlastec.2025.113106","DOIUrl":"10.1016/j.optlastec.2025.113106","url":null,"abstract":"<div><div>The development of plasmonic metal nanocomposites-decorated high-performance optical fibre sensors (OFS) for oil/gas detection remains challenging. Thus, gold-titania nanocomposites (Au-TiO₂NCs) were produced in deionized water (DIW) and ethanol (ET) using pulsed laser ablation in liquid (PLAL) method and characterized. Laser fluence (LF) was varied from 4.5 to 13.6 J/cm² to tailor the surface morphology, structural, optical, and physiochemical properties of six series of specimens. Crystallinity and purity of these NPs and NCs (optimum specimen from each series) were verified by XRD and FTIR measurement. TEM and SAED analyses of the optimum NCs prepared in DIW and ET (made at LF of 9.1 J/cm²) revealed their spherical morphology with the corresponding mean diameter of 11.59 ± 3.02 nm and 6.69 ± 3.94 nm. The studied plasmonic NCs made in DIW and ET showed fluorescence lifetime decay of 2.9 µs and 3.1 µs, respectively. The EDX spectra and elemental mapping of the optimum NPs and NCs confirmed their atomic composition and uniform distribution. The freshly grown NPs and NCs were used as sensing elements to coat the optical fIber, realizing a spectrum of high-quality sensors for petroleum grade N95 detection. All the designed sensors (coated with NPs and NCs) exhibited excellent sensitivity and linearity performance when exposed to petroleum N95 at various concentrations. It was asserted that the proposed products can contribute to the advancement of sustainable, reliable and cost-effective plasmonic sensors needed for diverse practical applications.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113106"},"PeriodicalIF":4.6,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908294","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":"Corrosion behavior of laser powder bed fusion TA2-Cu-Q345 composite plate subjected to picosecond laser shock peening","authors":"Chenhui Hu ,&nbsp;Zhen Zhang ,&nbsp;Weining Lu ,&nbsp;Jing Li ,&nbsp;Haijun Pan ,&nbsp;Lin Liu","doi":"10.1016/j.optlastec.2025.113120","DOIUrl":"10.1016/j.optlastec.2025.113120","url":null,"abstract":"<div><div>In this study, the corrosion behavior of laser powder bed fusion (LPBF) TA2-Cu-Q345 composite plate treated by picosecond laser shock processing (PsLSP) at 85 μJ, 145 μJ, and 200 μJ was evaluated. The corrosion mechanism was analyzed through experiments assessing surface roughness, microhardness, residual stress, phase structure, wettability and electrochemical test. The surface roughness, microhardness and residual stress of PsLSPed samples increases with the rising laser pulse energy. At 200 μJ, the microhardness and residual stress on the sample surface were 252.5 ± 30 HV and −196.5 ± 13.6 MPa, respectively. The corrosion current density (<em>i</em>_corr) of the PsLSPed sample was significantly reduced, with the 200 μJ PsLSPed sample exhibiting the lowest <em>i</em>_corr of 1.05E−06 A/cm². The corrosion morphology of PsLSPed samples showed fewer defects than that of untreated sample, which is attributed to the metal hardening layer on the surface that limits the further penetration of chloride ions into the TA2 matrix. Moreover, the high-hardness metal layer on the surface of PsLSPed samples effectively prevents crack formation. The primary reasons for the improved corrosion resistance were likely related to the hardening layer, residual stress, and TiO₂ oxide layer formed on the surface by PsLSP treatment, while surface roughness and hydrophilicity had minimal effects on corrosion resistance.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113120"},"PeriodicalIF":4.6,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143908293","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":"Effects of scanning strategies and heat treatments on the microstructure and mechanical performance of a Ni-based superalloy fabricated by laser powder bed fusion","authors":"Zhongyi Liu ,&nbsp;Han Zhang ,&nbsp;Zhenhua Zhang ,&nbsp;Liqiao Wang ,&nbsp;Xiaodan Wang ,&nbsp;Heng Zhang ,&nbsp;Ze Ji ,&nbsp;Quanquan Han","doi":"10.1016/j.optlastec.2025.113127","DOIUrl":"10.1016/j.optlastec.2025.113127","url":null,"abstract":"<div><div>The nickel-based superalloy has emerged as a leading candidate among existing aerospace alloys for laser powder bed fusion (LPBF) manufacturing. This study has explored the LPBF process of the SD-Ni03 superalloy, the design of which is based on the commercial alloy CM247LC, using three distinct scanning strategies. The mechanical performance of the resultant samples and the impact of heat treatment on SD-Ni03 were then examined. Our findings revealed anisotropic behaviour in the LPBF-fabricated samples, as evidenced by the variations in tensile properties between samples oriented parallel and perpendicular to the build direction (BD). Notably, SD-Ni03 samples fabricated with the zigzag-0°(Z0) strategy exhibited more pronounced anisotropy compared to those fabricated using the zigzag-90°(Z90) and island-90°(I90) strategies. Compared to the as-built (AB) samples, the ultimate tensile strength (UTS) values of heat-treated SD-Ni03-Z0 samples showed an increase of 24 % and −8% when tested parallelly or perpendicularly (respectively) to the BD at ambient temperature. At 900  °C, however, the UTS values decreased by 24 % and 23 %, respectively. Different heat treatment processes, including 5 different solution temperatures and 5 ageing temperatures, were applied to SD-Ni03-Z90 samples to investigate the effect of heat treatment on the volume fraction and morphologies of γ’ phases. The results indicated that solution treatment temperature mainly affected the size of the γ’ phase, while ageing treatment temperature mainly affected the volume fraction of γ’ phase. A remarkably high UTS value of 1597 MPa at ambient temperature was achieved through a solution treatment at 1070  °C for 2 h, followed by ageing at 750  °C for 24 h. The high UTS value could be attributed to the full precipitation and intermittent distribution of the primary γ’ and secondary γ’ phases. This study demonstrates that higher mechanical properties at 900  °C can be achieved in LPBF-fabricated precipitation-hardening alloys through direct ageing treatment.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113127"},"PeriodicalIF":4.6,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912096","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":"Impact of noise on machine learning models for simultaneously predicting water and oil levels using optical fiber sensors","authors":"Claunir Pavan ,&nbsp;Helder R.O. Rocha ,&nbsp;Arnaldo G. Leal-Junior ,&nbsp;Maria J. Pontes ,&nbsp;Marcelo E.V. Segatto","doi":"10.1016/j.optlastec.2025.113056","DOIUrl":"10.1016/j.optlastec.2025.113056","url":null,"abstract":"<div><div>We address the problem of simultaneously estimating the water-oil interface and total levels in three-phase separator tanks by applying three machine learning methods: Multilayer Perceptron (MLP), Kolmogorov-Arnold Networks (KAN), and Random Forest (RF). Data was collected from Fiber Bragg Grating-based optical sensors and processed to suppress outliers using the Local Outlier Factor algorithm. Hyperparameters for each model were optimized using Grid Search, and their performance was compared. The trained models were also exposed to scenarios with different levels of noise, and performance was evaluated. The results suggest that KAN performs effectively in predicting liquid levels, achieving a Root Mean Square Error of less than 3 mm and a Mean Absolute Percentage Error below 0.3% in scenarios without noise. Both MLP and KAN exhibit similar accuracy when the noise level is up to 1%. However, the MLP model outperforms KAN in higher noisy scenarios. On the other hand, the RF model shows the least effectiveness overall in noisy environments, though it does maintain a relatively stable maximum error across different noise levels. Therefore, we demonstrate that KAN has advantages in low-noise scenarios compared to conventional MLP and RF models. Conversely, MLP is more effective under higher noise conditions. These findings can aid in the research and development of monitoring systems.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113056"},"PeriodicalIF":4.6,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912814","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":"Fabrication of highly uniform laser-induced periodic structures on polycarbonate via UV femtosecond pulses","authors":"Matina Vlahou ,&nbsp;Nektaria Protopapa ,&nbsp;Stella Maragkaki ,&nbsp;George D. Tsibidis ,&nbsp;Emmanuel Stratakis","doi":"10.1016/j.optlastec.2025.113121","DOIUrl":"10.1016/j.optlastec.2025.113121","url":null,"abstract":"<div><div>In this work, we focus on the fabrication of highly uniform laser-induced periodic surface structures (LIPSS) on bulk polycarbonate (PC) using 258 nm femtosecond laser pulses. A systematic approach was pursued to investigate the influence of various laser parameters such as fluence, effective number of pulses, energy dose and polarisation on the features of the generated LIPSS. Experimental results showed that linearly polarized beams produce LIPSS with period comparable to the laser wavelength. Moreover, it was observed that the orientation of LIPSS is either parallel or perpendicular to the laser polarization, depending on the excitation level. These features are similar to the LIPSS formed on dielectrics, despite the considerably higher absorption and larger extinction coefficient (∼10⁻²) of polycarbonate at 258 nm. The orientation and features of the patterns at different excitation levels are explained using Sipe’s theory, while the excitation and induced carrier densities were quantified through the application of a theoretical physical model that describes ultrafast dynamics in polymers. Furthermore, observations revealed that low excitation levels with linearly polarized enhance the uniformity of LIPSS, whereas irradiating PC targets with circularly polarized beams leads to the formation of microscale topographies decorated with protruding nanosphered-like structures, with their size varying based on the laser conditions. A detailed analysis of the impact of the induced topographies on their wetting and optical properties demonstrated a steady increase in hydrophilicity over time, in contrast to a modest increase in optical absorbance. The results regarding the morphological features and properties of the induced topographies on PC are anticipated to support future efforts in creating patterned surfaces on polymeric materials for potential applications.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113121"},"PeriodicalIF":4.6,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912816","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":"Ultra-broadband incoherent sources based on laser-sustained plasma","authors":"He Hu ,&nbsp;Shichao Yang ,&nbsp;Zhaojiang Shi ,&nbsp;Xia Yu","doi":"10.1016/j.optlastec.2025.113098","DOIUrl":"10.1016/j.optlastec.2025.113098","url":null,"abstract":"<div><div>Laser-sustained plasma (LSP) featured by intense radiation in the ultra-broadband spectral range from vacuum ultraviolet to mid infrared, has attracted general interest in high resolution imaging, spectroscopy, and precision inspection. As high power fiber lasers have advanced in recent years, LSP-based techniques for broadband incoherent sources have emerged. However, despite numerous research efforts over the decades, there is still a lack of a comprehensive review of the influence of both gas parameters and laser parameters on LSP and their underlying mechanism. In this review, we summarized the state-of-the-art research results based on LSP techniques. Starting from the physical processes of absorption and radiation, key characteristics of LSP have been analyzed by considering critical parameters including plasma density, laser absorption coefficient and radiation coefficient. Subsequently, the effect of laser parameters on LSP characteristics and the possible mechanism are analyzed in detail. Moreover, the optical diagnostics methodologies of these parameters are compared and evaluated. Essential applications of LSP technology as a light source, in material processing and laser propulsion are summarized. Finally, we discuss the existing problems, possible solutions and future research outlook of LSP technology.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113098"},"PeriodicalIF":4.6,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904184","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":"Quasi-bound states in the continuum induced via surface roughness","authors":"Gyeong Cheol Park ,&nbsp;Kwangwook Park","doi":"10.1016/j.optlastec.2025.113070","DOIUrl":"10.1016/j.optlastec.2025.113070","url":null,"abstract":"<div><div>Regular structural perturbations have been widely introduced into optical metasurfaces to break their symmetry and excite quasi-bound states in the continuum (BICs), which possess a high-quality factor. Here, we investigate how the irregular roughness of 1D metasurfaces influences the disruption of structural symmetry and impacts the excitation of quasi-BIC. First, random roughness is introduced on the sidewalls of a 1D grating constituting a metasurface. Then, the excited resonance of a rough metasurface is compared with the quasi-BIC of a metasurface possessing regular asymmetry with a flat sidewall to verify that the excited resonance is due to the quasi-BIC. Furthermore, the influence of degree of roughness is examined by analyzing the resonance wavelength and the excited field intensity. As the roughness increases, the resonance wavelength distribution broadens toward longer wavelengths, and the largest field intensity increases, although lower intensities dominate overall. Second, the distribution of resonance wavelengths and the range of maximum field intensities are analyzed with an increase in the number of gratings with independent rough profiles in a super-cell. As additional gratings are incorporated into the super-cell, the resonance wavelength distribution converges to the true BIC wavelength. At the same time, the range of maximum field intensity gradually decreases. Last, we investigate rough metasurfaces covered with a homogeneous high-refractive-index layer and confirm the excitation of two quasi-BICs having opposite parities.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113070"},"PeriodicalIF":4.6,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904182","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":"Modified mode transformer for detecting large-range OAM modes for the Laguerre-Gaussian beams","authors":"Hongjie Xu ,&nbsp;Liulin Li ,&nbsp;Badreddine Merabet ,&nbsp;Bingyi Liu ,&nbsp;Sergey S. Stafeev ,&nbsp;Elena S. Kozlova ,&nbsp;Victor V. Kotlyar ,&nbsp;Zhongyi Guo","doi":"10.1016/j.optlastec.2025.113074","DOIUrl":"10.1016/j.optlastec.2025.113074","url":null,"abstract":"<div><div>Traditional signal multiplexing technologies have reached their limitations. Vortex beams exhibit a distinctive characteristic of orbital angular momentum (OAM), theoretically capable of providing infinite capacity, which allows for an increase in the information-carrying capacity of current optical networks, including both free-space optical (FSO) and fiber-based communication systems. In this paper, we propose an efficient approach to detect wide-range OAM modes using a mode transformer for the Laguerre-Gaussian (LG) beams. The mode transformer includes a phase mask (P1) that consists of three parts: the transformation term, the fan-out term, and the inverse term. And a phase corrector (P2). The fan-out mapper creates multiple copies of the transformed beams. After applying the phase mask, optical geometric transformations yield the optical matrix. Following phase correction, the light spots that form at the focal plane are identified by a CCD. We further extend the detection range by introducing an appropriate inverse phase to the P1 mask. Simulation tests have demonstrated outstanding detection performance, highlighting the potential of our proposed method to enhance the detection efficiency of multiplexed OAM beams.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113074"},"PeriodicalIF":4.6,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143904183","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}