Pub Date : 2025-04-27DOI: 10.1016/j.optlastec.2025.113031
Huailin Zhang , Zhenyang Cao , Wang Zhao , Guangni Zhou , Enqi Zhang , Sihai Luo , Weifeng He
To mitigate fretting wear damage in critical high-temperature moving components of aero-engines, such as turbine blades and disks, this study employed LSPwC to treat the surface of TiAl alloys and systematically analyzed their fretting wear behavior and damage mechanisms. The experimental results show that the wear depth of the LSPwCed samples decreased by 43.8% compared to the original samples, while the wear volume increased by 60.4%. After removing the surface remelted layer induced by LSPwC, the wear depth and wear volume decreased by 21.9% and 8.6%, respectively, compared to the original samples. The TiO2/Al2O3 ratio and structural defects such as microcracks and fusion holes in the surface remelted layer formed by LSPwC are the main reasons for the differences in the results. The increase in microhardness induced by LSPwC significantly enhances the overall wear resistance of the material.
{"title":"Improving room-temperature fretting wear performance of brittle TiAl alloy via laser shock peening without coating","authors":"Huailin Zhang , Zhenyang Cao , Wang Zhao , Guangni Zhou , Enqi Zhang , Sihai Luo , Weifeng He","doi":"10.1016/j.optlastec.2025.113031","DOIUrl":"10.1016/j.optlastec.2025.113031","url":null,"abstract":"<div><div>To mitigate fretting wear damage in critical high-temperature moving components of aero-engines, such as turbine blades and disks, this study employed LSPwC to treat the surface of TiAl alloys and systematically analyzed their fretting wear behavior and damage mechanisms. The experimental results show that the wear depth of the LSPwCed samples decreased by 43.8% compared to the original samples, while the wear volume increased by 60.4%. After removing the surface remelted layer induced by LSPwC, the wear depth and wear volume decreased by 21.9% and 8.6%, respectively, compared to the original samples. The TiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratio and structural defects such as microcracks and fusion holes in the surface remelted layer formed by LSPwC are the main reasons for the differences in the results. The increase in microhardness induced by LSPwC significantly enhances the overall wear resistance of the material.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113031"},"PeriodicalIF":4.6,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876651","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}
The laser shock forging assisted arc repair (LSF-AR) technology is newly developed. To validate the effectiveness of this technology, the residual stress and mechanical properties of DH36 steel repaired by arc repair (AR) and LSF-AR were comparatively investigated through numerical simulation and experiment. The simulated deformation values of the repaired sample were first compared with the experimental measured data to confirm the validity of the simulation settings. Afterwards, a comparative analysis was conducted on the residual stress distributions acquired from both numerical simulations and experimental measurements, which were found in good agreement. The results indicated that the AR sample exhibited significant tensile residual stress (TRS) in the weld seam, but LSF-AR notably reduced this TRS, with the TRS at the weld seam center decreasing from 395.4 MPa to 204.3 MPa. Compared to the AR sample, the LSF-AR sample showed improved tensile strength and elongation. This study validated the feasibility of applying LSF method during AR processes to achieve low residual stress and high-performance repair.
{"title":"Investigations on the residual stress and mechanical properties of DH36 steel repaired by laser shock forging assisted arc repair method","authors":"Yuanqing Chi, Kangsheng Zheng, Qi Zhang, Zhijie Zhou, Aoyu Yan, Baijun Zhang, Yongkang Zhang","doi":"10.1016/j.optlastec.2025.113058","DOIUrl":"10.1016/j.optlastec.2025.113058","url":null,"abstract":"<div><div>The laser shock forging assisted arc repair (LSF-AR) technology is newly developed. To validate the effectiveness of this technology, the residual stress and mechanical properties of DH36 steel repaired by arc repair (AR) and LSF-AR were comparatively investigated through numerical simulation and experiment. The simulated deformation values of the repaired sample were first compared with the experimental measured data to confirm the validity of the simulation settings. Afterwards, a comparative analysis was conducted on the residual stress distributions acquired from both numerical simulations and experimental measurements, which were found in good agreement. The results indicated that the AR sample exhibited significant tensile residual stress (TRS) in the weld seam, but LSF-AR notably reduced this TRS, with the TRS at the weld seam center decreasing from 395.4 MPa to 204.3 MPa. Compared to the AR sample, the LSF-AR sample showed improved tensile strength and elongation. This study validated the feasibility of applying LSF method during AR processes to achieve low residual stress and high-performance repair.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113058"},"PeriodicalIF":4.6,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876927","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}
Due to the limited dynamic range of cameras, reconstruction tasks on high dynamic range surfaces often exhibit overexposed and underexposed regions in the captured images, compromising measurement accuracy and completeness. Existing high dynamic range measurement techniques perform 3D reconstruction directly using image intensity or multi-exposure fusion methods. These techniques cannot simultaneously meet the requirements of single-shot measurement, high precision, high completeness, and ease of use. In this article, we propose a novel measurement method with single shot to address these challenges. Different from existing methods, a multi-view stereo pipeline is proposed to fully utilize the properly exposed areas of different views. By multi-view matching based on photometric and geometric consistency, the depth and normal vector for each pixel in every view will be obtained. The depth and normal vector can be combined into a spatial slanted plane, initializing the first-order shape function parameters. A multi-view digital speckle correlation method is proposed to optimize the plane parameters. Finally, the plane parameters are integrated to produce the depth map fusion. A four-camera measurement system with a photolithographic speckle projection module is developed for experimental validation. Extensive quantitative and qualitative experiments demonstrate that the proposed method achieves the measurement accuracy of 0.04–0.07 mm, meeting the requirements of industrial applications.
{"title":"A novel method for high dynamic range optical measurement with single shot by multi-view stereo","authors":"Haitao Wu , Yanzhen Dong , Xiaobo Chen , Juntong Xi","doi":"10.1016/j.optlastec.2025.112930","DOIUrl":"10.1016/j.optlastec.2025.112930","url":null,"abstract":"<div><div>Due to the limited dynamic range of cameras, reconstruction tasks on high dynamic range surfaces often exhibit overexposed and underexposed regions in the captured images, compromising measurement accuracy and completeness. Existing high dynamic range measurement techniques perform 3D reconstruction directly using image intensity or multi-exposure fusion methods. These techniques cannot simultaneously meet the requirements of single-shot measurement, high precision, high completeness, and ease of use. In this article, we propose a novel measurement method with single shot to address these challenges. Different from existing methods, a multi-view stereo pipeline is proposed to fully utilize the properly exposed areas of different views. By multi-view matching based on photometric and geometric consistency, the depth and normal vector for each pixel in every view will be obtained. The depth and normal vector can be combined into a spatial slanted plane, initializing the first-order shape function parameters. A multi-view digital speckle correlation method is proposed to optimize the plane parameters. Finally, the plane parameters are integrated to produce the depth map fusion. A four-camera measurement system with a photolithographic speckle projection module is developed for experimental validation. Extensive quantitative and qualitative experiments demonstrate that the proposed method achieves the measurement accuracy of 0.04–0.07 mm, meeting the requirements of industrial applications.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 112930"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874449","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}
Pub Date : 2025-04-26DOI: 10.1016/j.optlastec.2025.112936
Hao Cui , Xingqiang Li , Rigang Cong , Chuanxing Liu , Jinsong Du
The key geometric parameters of miniaturized rotational parts significantly influence the overall performance and service life of equipment, such as bore diameter, roundness, cylindricity, generatrix contour, etc. However, most existing measurement technologies are aimed at certain types of parameters and fail to provide full-scale and high-precision measurements, especially when measuring space is limited. In this paper, a 4-axis linkage spatial measurement system is established, equipped with a precision air-floating turntable and a compact fiber optic probe. Innovations include: (1) An efficient 4-axis linkage calibration method is proposed. This method can achieve precise calibration of the laser direction vector or the rotation axis position with only a single scan; (2) On this basis, a polar-coordinate measurement model for any positive section of rotational parts is proposed, eliminating the negative impact of part offset on measurement accuracy. Experimental results show that the measurement error of the diameter, the roundness and the cylindricity is approximately , and , respectively. The average measurement error of the generatrix contour is . Compared with the traditional contact coordinate measuring machine, the overall measurement efficiency is improved by about 67%, demonstrating that this method meets the requirements for on-site efficient and precise measurement of miniaturized rotational parts.
{"title":"An efficient on-site calibration method and precise measurement model for miniaturized rotational parts based on four-axis linkage spatial measurement system","authors":"Hao Cui , Xingqiang Li , Rigang Cong , Chuanxing Liu , Jinsong Du","doi":"10.1016/j.optlastec.2025.112936","DOIUrl":"10.1016/j.optlastec.2025.112936","url":null,"abstract":"<div><div>The key geometric parameters of miniaturized rotational parts significantly influence the overall performance and service life of equipment, such as bore diameter, roundness, cylindricity, generatrix contour, etc. However, most existing measurement technologies are aimed at certain types of parameters and fail to provide full-scale and high-precision measurements, especially when measuring space is limited. In this paper, a 4-axis linkage spatial measurement system is established, equipped with a precision air-floating turntable and a compact fiber optic probe. Innovations include: (1) An efficient 4-axis linkage calibration method is proposed. This method can achieve precise calibration of the laser direction vector or the rotation axis position with only a single scan; (2) On this basis, a polar-coordinate measurement model for any positive section of rotational parts is proposed, eliminating the negative impact of part offset on measurement accuracy. Experimental results show that the measurement error of the diameter, the roundness and the cylindricity is approximately <span><math><mrow><mn>3</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, <span><math><mrow><mn>2</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> and <span><math><mrow><mn>2</mn><mo>.</mo><mn>8</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, respectively. The average measurement error of the generatrix contour is <span><math><mrow><mn>4</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>. Compared with the traditional contact coordinate measuring machine, the overall measurement efficiency is improved by about 67%, demonstrating that this method meets the requirements for on-site efficient and precise measurement of miniaturized rotational parts.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 112936"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874451","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}
Pub Date : 2025-04-26DOI: 10.1016/j.optlastec.2025.113017
Xiuyu Chen , Lin Qin , Jinlong Huang , Yufang Liu , Shuwen Zheng , Mengdan Qian
Controlling thermal radiation in the infrared (IR) spectrum is pivotal for energy management and military camouflage, sparking heightened research interest. This study introduces a wavelength-selective thermal emitter (WSTE) utilizing a metal-dielectric-metal (MDM) structure composed of an Al/Ge/Al periodic array. The WSTE exhibits low emissivity in the IR atmospheric windows (ɛ3-5µm = 0.2 and ɛ8-14µm = 0.2), fulfilling IR camouflage requirements while achieving high emissivity in the non-atmospheric window (ɛ5-8µm = 0.6) for efficient thermal dissipation to achieve radiative cooling. Furthermore, the WSTE demonstrates strong absorption at 10.6 µm, enhancing its laser stealth capability. Measures data substantiate the alignment between simulations and experiments, showing stable performance at temperatures up to 350 °C. When compared to conventional low-emissivity stealth materials (Al film), the surface temperature of the WSTE could be 18.42 ℃ lower than that of the Al film at 45 W, indicating excellent thermal management capability. The WSTE’s straightforward yet robust design exhibits exceptional high-temperature resistance, ease of fabrication, and scalability for mass production, positioning it as a promising candidate for applications demanding infrared stealth and radiative cooling.
{"title":"Controlling thermal radiation by metasurface for infrared and laser compatible stealth with radiative cooling","authors":"Xiuyu Chen , Lin Qin , Jinlong Huang , Yufang Liu , Shuwen Zheng , Mengdan Qian","doi":"10.1016/j.optlastec.2025.113017","DOIUrl":"10.1016/j.optlastec.2025.113017","url":null,"abstract":"<div><div>Controlling thermal radiation in the infrared (IR) spectrum<!--> <!-->is pivotal for energy<!--> <!-->management and military camouflage, sparking heightened research interest. This study introduces a wavelength-selective thermal emitter (WSTE) utilizing a metal-dielectric-metal (MDM) structure composed of an Al/Ge/Al periodic array. The WSTE exhibits low emissivity in the IR atmospheric windows (ɛ<sub>3-5µm</sub> = 0.2 and<!--> <!-->ɛ<sub>8-14µm</sub> = 0.2), fulfilling IR camouflage requirements while achieving high emissivity in the non-atmospheric window (ɛ<sub>5-8µm</sub> = 0.6) for efficient thermal dissipation to achieve radiative cooling. Furthermore, the WSTE demonstrates strong absorption at 10.6 µm, enhancing its laser stealth capability. Measures data substantiate the alignment between simulations and experiments, showing stable performance at temperatures up to 350 °C. When compared to conventional low-emissivity stealth materials (Al film), the surface temperature of the WSTE could be 18.42 ℃ lower than that of the Al film at 45 W, indicating excellent thermal management capability. The WSTE’s straightforward yet robust design exhibits exceptional high-temperature resistance, ease of fabrication, and scalability for mass production, positioning it as a promising candidate for applications demanding infrared stealth and radiative cooling.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113017"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877321","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}
Pub Date : 2025-04-26DOI: 10.1016/j.optlastec.2025.112996
Yongfeng Xie, Hong Zhang, Yan Cheng, Yuehong Zhu, Junhong Liu
We present an electro-optic (EO) Q-switched Er:ZBLAN fiber laser based on a customized La3Ga5SiO14 (LGS) crystal. We investigate the effects of pump power and repetition rate on the laser output. At a repetition rate of 100 Hz, the laser generates stable pulses with a pulse width of 74 ns, pulse energy of 350 μJ, and peak power of 4.6 kW. At a repetition rate of 10 kHz, the laser achieves stable pulses with a pulse width of 159 ns, pulse energy of 15.7 μJ, and peak power of 99 W. Additionally, the laser exhibits a wavelength tuning range of approximately 90 nm at 2.7 μm under Q-switching modulation at 5 kHz. The results indicate that the laser provides stable pulse output in the 2.7 μm wavelength region.
{"title":"Wavelength tunable actively Q-switched Er:ZBLAN fiber laser using LGS crystal as electro-optic modulator","authors":"Yongfeng Xie, Hong Zhang, Yan Cheng, Yuehong Zhu, Junhong Liu","doi":"10.1016/j.optlastec.2025.112996","DOIUrl":"10.1016/j.optlastec.2025.112996","url":null,"abstract":"<div><div>We present an electro-optic (EO) Q-switched Er:ZBLAN fiber laser based on a customized La<sub>3</sub>Ga<sub>5</sub>SiO<sub>14</sub> (LGS) crystal. We investigate the effects of pump power and repetition rate on the laser output. At a repetition rate of 100 Hz, the laser generates stable pulses with a pulse width of 74 ns, pulse energy of 350 μJ, and peak power of 4.6 kW. At a repetition rate of 10 kHz, the laser achieves stable pulses with a pulse width of 159 ns, pulse energy of 15.7 μJ, and peak power of 99 W. Additionally, the laser exhibits a wavelength tuning range of approximately 90 nm at 2.7 μm under Q-switching modulation at 5 kHz. The results indicate that the laser provides stable pulse output in the 2.7 μm wavelength region.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 112996"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874450","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}
Pub Date : 2025-04-26DOI: 10.1016/j.optlastec.2025.113001
Meichen Xia , Yuxuan Zhang , Hong Peng , Zhicai Liu , Jun Guo
Infrared small target detection (IRSTD) has become a significant challenge due to the weak target, complex and variable backgrounds, and harsh imaging environments. Currently, most models are based on the U-net framework or its improved versions, but they often overlook the in-depth optimization of the output features. In response to this situation, this paper innovatively proposes a network specifically designed for this task, called UFNet-NSNP. The core of this network is its unique Ultra Fusion Net (UFNet), which efficiently integrates multiscale and multilevel features to significantly enhance the detail expressiveness of images. In addition, UFNet-NSNP introduces a novel Convolutional Attention Fusion Module (CAFM-SNP), which processes and further fuses the output features of the UFNet through cascaded Dilated convolutions and attention mechanisms to comprehensively enhance the global information capture capability of images. At the same time, the network has designed a nonlinear attention mechanism (NA) based on the nonlinear spiking mechanism, and by combining this mechanism with the spatial attention mechanism (SA), it has created a new attention module(NSNP-A). This module can enhance the nonlinear features of images. Experiments were conducted on the NUAA-SIRST and IRSTD-1k datasets. The experimental results show that UFNet-NSNP achieved an of 77.46% on the NUAA-SIRST dataset and 69.21% on the IRSTD-1k dataset, it demonstrates superior comprehensive performance compared to existing state-of-the-art (SOTA) methods. The code will be available at https://github.com/ZYX-111222/UFNet-NSNP.
{"title":"A ultra fusion network model based on nonlinear spiking neural P systems for infrared small target detection","authors":"Meichen Xia , Yuxuan Zhang , Hong Peng , Zhicai Liu , Jun Guo","doi":"10.1016/j.optlastec.2025.113001","DOIUrl":"10.1016/j.optlastec.2025.113001","url":null,"abstract":"<div><div>Infrared small target detection (IRSTD) has become a significant challenge due to the weak target, complex and variable backgrounds, and harsh imaging environments. Currently, most models are based on the U-net framework or its improved versions, but they often overlook the in-depth optimization of the output features. In response to this situation, this paper innovatively proposes a network specifically designed for this task, called UFNet-NSNP. The core of this network is its unique Ultra Fusion Net (UFNet), which efficiently integrates multiscale and multilevel features to significantly enhance the detail expressiveness of images. In addition, UFNet-NSNP introduces a novel Convolutional Attention Fusion Module (CAFM-SNP), which processes and further fuses the output features of the UFNet through cascaded Dilated convolutions and attention mechanisms to comprehensively enhance the global information capture capability of images. At the same time, the network has designed a nonlinear attention mechanism (NA) based on the nonlinear spiking mechanism, and by combining this mechanism with the spatial attention mechanism (SA), it has created a new attention module(NSNP-A). This module can enhance the nonlinear features of images. Experiments were conducted on the NUAA-SIRST and IRSTD-1k datasets. The experimental results show that UFNet-NSNP achieved an <span><math><mrow><mi>I</mi><mi>o</mi><mi>U</mi></mrow></math></span> of 77.46% on the NUAA-SIRST dataset and 69.21% on the IRSTD-1k dataset, it demonstrates superior comprehensive performance compared to existing state-of-the-art (SOTA) methods. The code will be available at <span><span>https://github.com/ZYX-111222/UFNet-NSNP</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113001"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874452","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}
Pub Date : 2025-04-26DOI: 10.1016/j.optlastec.2025.112981
Mohamed G. Mahmoud , Mohamed Farhat O. Hameed , Salah S.A. Obayya
This paper introduces a pioneering inverse design paradigm for the refinement and enhancement of photonic devices utilizing an AI-based algorithm known as reinforcement learning (RL). The efficacy of this novel model is examined through calibrating a selected photonic device geometry to achieve the desired device response. A comparative analysis reveals the remarkable potency of the RL framework as it outperformed conventional optimizers, such as particle swarm optimization (PSO) and a modified version of the trust region algorithm (MTR). The RL framework yielded substantial enhancement in the device performance by 41.8% for the PSO design and 71.9% for the MTR design. Additionally, the RL framework demonstrated fast convergence toward the most optimal design in only 55 iterations, which is a stark departure from the 1000 iterations required by the PSO algorithm, and the 1700 iterations required by the MTR algorithm. Furthermore, the A2C-RL model was extended to enhance the geometry of a different PCF, while simultaneously incorporating liquid crystal infiltration into selected air holes in the PCF to produce wide-band ultra-flattened dispersion compensators, showcasing the versatility and effectiveness of A2C-RL in generating unconventional design choices, while reaching the best possible design. Furthermore, the generalizability of the proposed model is rigorously illustrated by achieving a 15% enhancement in the bandwidth of a Ku-band broadband metamaterial absorber within merely seven iterations. This result underscores the efficacy and adaptability of the A2C-RL model, affirming its potential for broader application across a wide range of photonic devices.
{"title":"An alternative AI-based inverse design paradigm for photonic devices","authors":"Mohamed G. Mahmoud , Mohamed Farhat O. Hameed , Salah S.A. Obayya","doi":"10.1016/j.optlastec.2025.112981","DOIUrl":"10.1016/j.optlastec.2025.112981","url":null,"abstract":"<div><div>This paper introduces a pioneering inverse design paradigm for the refinement and enhancement of photonic devices utilizing an AI-based algorithm known as reinforcement learning (RL). The efficacy of this novel model is examined through calibrating a selected photonic device geometry to achieve the desired device response. A comparative analysis reveals the remarkable potency of the RL framework as it outperformed conventional optimizers, such as particle swarm optimization (PSO) and a modified version of the trust region algorithm (MTR). The RL framework yielded substantial enhancement in the device performance by 41.8% for the PSO design and 71.9% for the MTR design. Additionally, the RL framework demonstrated fast convergence toward the most optimal design in only 55 iterations, which is a stark departure from the 1000 iterations required by the PSO algorithm, and the 1700 iterations required by the MTR algorithm. Furthermore, the A2C-RL model was extended to enhance the geometry of a different PCF, while simultaneously incorporating liquid crystal infiltration into selected air holes in the PCF to produce wide-band ultra-flattened dispersion compensators, showcasing the versatility and effectiveness of A2C-RL in generating unconventional design choices, while reaching the best possible design. Furthermore, the generalizability of the proposed model is rigorously illustrated by achieving a 15% enhancement in the bandwidth of a Ku-band broadband metamaterial absorber within merely seven iterations. This result underscores the efficacy and adaptability of the A2C-RL model, affirming its potential for broader application across a wide range of photonic devices.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 112981"},"PeriodicalIF":4.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876650","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}
Pub Date : 2025-04-25DOI: 10.1016/j.optlastec.2025.112940
Jeroen Missinne, Rik Verplancke, Yao-Tung Chang , Geert Van Steenberge
This paper presents a versatile microlens integration platform designed to address key packaging challenges in photonic integrated circuits (PICs), particularly in enhancing coupling efficiency, increasing working distance, and enabling the hybrid integration of external optical components, such as isolators, which are difficult to integrate monolithically. We first describe multiple integration strategies for microlenses with PICs toward achieving relaxed alignment tolerances and extended working distances when interfacing with fiber arrays. To demonstrate the platform’s possibilities, we detail two specific use cases. The first involves a long working distance expanded beam interface for O-band datacom applications, where a microlensed PIC, paired with a microlensed connector, achieves a 3.8 mm working distance with a modest additional insertion loss of 0.85 dB per interface attributed to integration of the lenses. This configuration offers improved lateral and longitudinal alignment tolerances, making it well-suited for pluggable connector applications. The second use case demonstrates the integration of an optical isolator within the coupling interface of a C-band PIC, achieving an isolator insertion loss of 1.2 dB and a broad 1 dB bandwidth of 80 nm, with an extinction ratio of -20 dB at the target 1540 nm wavelength. Together, these use cases highlight the potential of microlens-based solutions to address PIC packaging requirements, offering enhanced tolerance management and enabling new possibilities for hybrid integration of complex optical functionalities.
{"title":"Microlenses on photonic integrated circuits enable flexible packaging and optical isolator integration","authors":"Jeroen Missinne, Rik Verplancke, Yao-Tung Chang , Geert Van Steenberge","doi":"10.1016/j.optlastec.2025.112940","DOIUrl":"10.1016/j.optlastec.2025.112940","url":null,"abstract":"<div><div>This paper presents a versatile microlens integration platform designed to address key packaging challenges in photonic integrated circuits (PICs), particularly in enhancing coupling efficiency, increasing working distance, and enabling the hybrid integration of external optical components, such as isolators, which are difficult to integrate monolithically. We first describe multiple integration strategies for microlenses with PICs toward achieving relaxed alignment tolerances and extended working distances when interfacing with fiber arrays. To demonstrate the platform’s possibilities, we detail two specific use cases. The first involves a long working distance expanded beam interface for O-band datacom applications, where a microlensed PIC, paired with a microlensed connector, achieves a 3.8<!--> <!-->mm working distance with a modest additional insertion loss of 0.85<!--> <!-->dB per interface attributed to integration of the lenses. This configuration offers improved lateral and longitudinal alignment tolerances, making it well-suited for pluggable connector applications. The second use case demonstrates the integration of an optical isolator within the coupling interface of a C-band PIC, achieving an isolator insertion loss of 1.2<!--> <!-->dB and a broad 1<!--> <!-->dB bandwidth of 80<!--> <!-->nm, with an extinction ratio of -20<!--> <!-->dB at the target 1540<!--> <!-->nm wavelength. Together, these use cases highlight the potential of microlens-based solutions to address PIC packaging requirements, offering enhanced tolerance management and enabling new possibilities for hybrid integration of complex optical functionalities.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 112940"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868611","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}
We first report on the 2550 nm mid-infrared acousto-optic Q-switched Ho:YLF/SrWO4 intracavity Raman laser in-band pumped by a 1940 nm Tm fiber laser. The output performances of Ho:YLF/SrWO4 Raman laser were investigated at several different pulse repetition frequencies. Based on the stimulated Raman scattering effect, the 2065 nm fundamental laser was converted to the 2550 nm Raman laser. At the pulse repetition frequency of 4 kHz, the maximum average output power of 900 mW was achieved with a pulse width of 17.07 ns. The corresponding single pulse energy and peak power were 225 μJ and 13.18 kW, respectively.
{"title":"Tm fiber laser in-band pumped Ho:YLF/SrWO4 intracavity mid-infrared Raman laser at 2550 nm","authors":"Xiaofan Jing, Xinlu Zhang, Changchang Shen, Jinjer Huang","doi":"10.1016/j.optlastec.2025.113033","DOIUrl":"10.1016/j.optlastec.2025.113033","url":null,"abstract":"<div><div>We first report on the 2550 nm mid-infrared acousto-optic Q-switched Ho:YLF/SrWO<sub>4</sub> intracavity Raman laser in-band pumped by a 1940 nm Tm fiber laser. The output performances of Ho:YLF/SrWO<sub>4</sub> Raman laser were investigated at several different pulse repetition frequencies. Based on the stimulated Raman scattering effect, the 2065 nm fundamental laser was converted to the 2550 nm Raman laser. At the pulse repetition frequency of 4 kHz, the maximum average output power of 900 mW was achieved with a pulse width of 17.07 ns. The corresponding single pulse energy and peak power were 225 μJ and 13.18 kW, respectively.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113033"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868612","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}
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