Optics & Laser Technology最新文献_第5页

Geometric calibration for photometric stereo under near-field point light sources using spheres 在近场点光源下使用球体进行光度立体的几何校准

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111557

Jian Yu, Yuchong Chen, Feipeng Da

{"title":"Geometric calibration for photometric stereo under near-field point light sources using spheres","authors":"Jian Yu, Yuchong Chen, Feipeng Da","doi":"10.1016/j.optlastec.2024.111557","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111557","url":null,"abstract":"Spheres are commonly employed for both camera calibration and light calibration. The apparent contours of spheres are utilized to determine the camera’s intrinsic parameters, while the highlights on the sphere aid in estimating the light direction. This paper introduces a novel calibration method using spheres to simultaneously calibrate both the camera and light sources. The reflected irradiance distribution of the Lambertian sphere is analyzed under illumination from a near-field point light source. Consequently, points with the same luminance form coaxial circles. Their imaging equations are formulated under a general projection model, offering orthogonal constraints on the image of the absolute conic for fully calibrating the camera. Next, the geometric determination of the sphere centers and point light source positions is implemented. Finally, a photometric constraint is constructed to minimize the discrepancy between the synthetic and real images of the sphere, aiming to optimize the entire parameters of the system. The experiments are executed on synthetic and real datasets, with results indicating the effectiveness and precision of the proposed method.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Achieving zero efficiency droop in highly efficient N-polar AlGaN tunnel junction-based 254 nm DUV LED 在基于高效 N 极 AlGaN 隧道结的 254 nm DUV LED 中实现零效率下降

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111567

Khalid Ayub, Banaras Khan, Yuhuai Liu, M. Nawaz Sharif, M. Ajmal Khan, Hideki Hirayama

{"title":"Achieving zero efficiency droop in highly efficient N-polar AlGaN tunnel junction-based 254 nm DUV LED","authors":"Khalid Ayub, Banaras Khan, Yuhuai Liu, M. Nawaz Sharif, M. Ajmal Khan, Hideki Hirayama","doi":"10.1016/j.optlastec.2024.111567","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111567","url":null,"abstract":"The Minamata Convention of 2020 mandates the replacement of conventional mercury UV lamps with deep ultraviolet (DUV) light-emitting diodes (LEDs) emitting at 254 nm. But both the traditional DUV LEDs (C-LEDs) and tunnel junction (TJ)-based UVC LEDs face challenges such as high operating voltages and inefficient hole injection. Utilizing p-AlGaN and n-AlGaN layers-based TJ in DUV LEDs shows promise in addressing these issues, particularly in mitigating contact resistance and improving hole injection efficiency at the 254 nm emission wavelength. This study presents an approach to manipulate quantum tunnelling probability in n-AlGaN/p-AlGaN tunnel junctions by optimizing doping levels and thickness using APSYS Software simulations. The result is a suppression of Auger recombination and increased radiative recombination rates in 254 nm TJ-based DUV LEDs compared to C-LED. Theoretical modeling shows an internal quantum efficiency (IQE) of approximately 88 % with zero efficiency droop in TJ-based LEDs, a significant improvement over the approximately 66 % IQE with a 53 % efficiency droop in C-LEDs. This study reveals the highest theoretically possible IQE of 88 % at a 254 nm emission wavelength in TJ-based LED, with no efficiency droop. Moreover, TJ-LEDs show linear increases in light output powers (LOP) with varying current densities due to lower Auger recombination rates in their multi-quantum wells (MQWs). Notably, operating voltages reduce significantly from 21 V to 5.4 V under 200 A/cm operation, attributed to optimized TJ thickness and doping, along with a careful selection of lower Al-content in the contact layer. These findings pave the way for enhanced UV emitter growth using techniques like metal–organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE), promising advancements in biomedical applications.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"193 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

MGRCFusion: An infrared and visible image fusion network based on multi-scale group residual convolution MGRCFusion：基于多尺度群残差卷积的红外和可见光图像融合网络

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111576

Pan Zhu, Yufei Yin, Xinglin Zhou

引用次数: 0

A microwave photonic mixer based on Stimulated Brillouin Scattering with high image rejection capacity 基于受激布里渊散射的微波光子混频器具有高图像抑制能力

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111422

Wenqi Yu, Qianqian Jia, Guansu Xing, Jinye Li, Jianguo Liu, Canwen Zou

引用次数: 0

Customizable dual-resonance sensing empowered by coupled quasi-bound states in the continuum 利用连续体中的耦合准约束态实现可定制的双共振传感

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111544

Xiao-Qing Luo, Yaojie Zhou, Qinke Liu, Zhendong Lu, Sha Chen, Yan Li, W.M. Liu

{"title":"Customizable dual-resonance sensing empowered by coupled quasi-bound states in the continuum","authors":"Xiao-Qing Luo, Yaojie Zhou, Qinke Liu, Zhendong Lu, Sha Chen, Yan Li, W.M. Liu","doi":"10.1016/j.optlastec.2024.111544","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111544","url":null,"abstract":"The quasi-bound states in the continuum (QBIC) have drawn increasing attention in optical metasurfaces derived from their ultrahigh quality factors, and show the utility to enhance the sensitivity of optical sensing. However, conventional single-resonance sensing may be inaccurate and unreliable, and then the dual-resonance sensing governed by the coupled QBIC is desired but remains elusive. Here, we show that the coupled QBIC modes can be leveraged to unfold dual-resonance refractive index sensing in the hybrid all-dielectric metasurface. Specifically, it is revealed that the toroidal dipole mode can be realized with strong electric field enhancement, enabling the implementation of anapole mode in the telecom short-wavelength band (1460–1530 nm). Under different linearly polarized illuminations, the dual symmetry-protected QBIC modes dominated by the electric quadrupole resonance can be fulfilled in the telecom extended-wavelength band (1360–1460 nm). Within this framework, the polarization-dependent dual symmetry-protected QBIC modes selectively coupled with the toroidal dipole mode or the anapole mode can not only uncover the transformation from Fano resonance to analog of electromagnetically induced transparency, but also manifest two types of high-sensitivity dual-resonance refractive index sensing in the telecom extended-wavelength and short-wavelength bands. The dual-resonance refractive index sensing can also be extended to telecom long-wavelength band (1565–1625 nm) and ultra-long-wavelength band (1625–1675 nm) with enhanced sensitivity. These results offer exploration potential for multi-channel sensing, optical modulators, and slow-light devices.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wide-range vision-based position measurement for linear servo-motor mover 基于视觉的线性伺服电机移动装置大范围位置测量

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111541

Xia Yang, Jianting Mai, Wei Wang

引用次数: 0

Three-dimensional measurements of the in-cylinder diesel flame development under low crank speeds based on computed tomography 基于计算机断层扫描的低曲柄转速下柴油机缸内火焰发展的三维测量结果

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111574

Yu Gao, Haiyan Chen, Yue Wu, Wenqi Men

引用次数: 0

The performace of (TbBiCa)3Fe5O12 magneto-optical films at 1064 nm after hydrogen atmosphere annealing and ion beam polishing 氢气退火和离子束抛光后的 1064 纳米波长 (TbBiCa)3Fe5O12 磁光薄膜的性能

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111528

Jingyan Yu, Qinghui Yang, Ding Zhang, Xia Xiang, Bo Li, Yong Jiang, Yuanjing Zhang, Han Li, Feng Wang, Shuting Yang, Ihor I. Syvorotka, Huaiwu Zhang

{"title":"The performace of (TbBiCa)3Fe5O12 magneto-optical films at 1064 nm after hydrogen atmosphere annealing and ion beam polishing","authors":"Jingyan Yu, Qinghui Yang, Ding Zhang, Xia Xiang, Bo Li, Yong Jiang, Yuanjing Zhang, Han Li, Feng Wang, Shuting Yang, Ihor I. Syvorotka, Huaiwu Zhang","doi":"10.1016/j.optlastec.2024.111528","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111528","url":null,"abstract":"The laser damage properties of magneto-optical (MO) materials are the most important constraint for their application in high-power laser systems in the near-infrared (NIR) band. Rare-earth ion doped garnet (RIG) materials are widely used in optical communication systems and compact laser systems due to their superior MO properties —— small size and low driving magnetic field. In this study, high-quality (TbBiCa)FeO films with hundreds of microns thickness were fabricated by liquid phase epitaxy (LPE) method. These films have lower optical absorption than conventional (TbBi)FeO films after annealing in reducing atmosphere while possessing outstanding magneto-optical properties and their optical and MO properties are investigated in detail, which has a high specific faraday rotation angle of 1413 deg/cm at 1310 nm and 2647 deg/cm at 1064 nm, and transmittance is 51.2 % at 1064 nm and 71.6 % at 1310 nm. After that, ion beam polishing (IBP) treated the samples at different depths, and atomic force microscopy (AFM) was used to observe their surface morphology. Finally, the laser-induced damage threshold (LIDT) of samples was tested by a multi-frequency laser in different frequencies using the R-on-1 method. The LIDT of (TbBiCa)FeO irradiated by a multi-frequency at 50 kHz is 10.92 J/cm. Scanning electron microscopy (SEM) and optical microscopy were used to observe the surface morphology of the sample after the damage.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-order Hermite-Gaussian modes and optical vortices generated in an efficient Yb:YAG microchip laser by manipulating gain distribution 通过操纵增益分布在高效 Yb:YAG 微芯片激光器中产生高阶赫米特-高斯模式和光涡旋

Optics & Laser Technology Pub Date : 2024-08-08 DOI: 10.1016/j.optlastec.2024.111584

Xingyu Zhu, Jianwei Yang, Yufei Chen, Hongsen He, Jun Dong

{"title":"High-order Hermite-Gaussian modes and optical vortices generated in an efficient Yb:YAG microchip laser by manipulating gain distribution","authors":"Xingyu Zhu, Jianwei Yang, Yufei Chen, Hongsen He, Jun Dong","doi":"10.1016/j.optlastec.2024.111584","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111584","url":null,"abstract":"Optical vortices carrying orbital angular momentum with large topological charges have wide applications on optical communication, high capacity storage, high resolution imaging. Hermite-Gaussian (HG) mode lasers have been widely used to convert optical vortices with astigmatic mode converter. Here, high-order HG mode microchip laser has been demonstrated by manipulating gain distribution inside Yb:YAG gain medium. HG mode lasers with tunable from 0 to 21 have been generated by adjusting the distance between -axis focal spot of single-emitter laser diode and Yb:YAG crystal thin plate (Δz). At a constant pump power of 4.55 W, output power decreases from 977 mW for TEM mode laser to 652 mW for HG mode laser as Δz increases from 2.9 mm to 10.8 mm. Output power of 750 mW and optical conversion efficiency of 15 % are achieved for HG mode laser. HG mode lasers oscillate in multi-longitudinal-mode, and laser wavelength is kept constant independent on . Optical vortices with tunable topological charge up to 24 are converted from high beam quality HG mode lasers with an astigmatic mode converter. By manipulating pump beam distribution of single-emitter laser diode, microchip laser is a solid platform for efficiently generating high-order HG lasers and conversion to desired optical vortices.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gradient-based strategy of designing cascaded phase holograms for arbitrary distribution behind arbitrary aperture 基于梯度的级联相位全息图设计策略，适用于任意孔径后的任意分布

Optics & Laser Technology Pub Date : 2024-08-07 DOI: 10.1016/j.optlastec.2024.111489

Hengyang Li, Jiaming Xu, Qin Luo, Cong Hu, Yu Xiao, Xiahui Tang, Gang Xu, Yingxiong Qin

{"title":"Gradient-based strategy of designing cascaded phase holograms for arbitrary distribution behind arbitrary aperture","authors":"Hengyang Li, Jiaming Xu, Qin Luo, Cong Hu, Yu Xiao, Xiahui Tang, Gang Xu, Yingxiong Qin","doi":"10.1016/j.optlastec.2024.111489","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111489","url":null,"abstract":"Aperture, flexibly defined as common-seen periphery-blocked structures, or special-shaped patterns, or even with artificial-designed complex amplitude modulating function, are inevitably a core factor of optical system that forces the light path deviate from the unconstrained situation. To bridge the gap between the ideal simplified phase modulation system and the real aperture-constrained system, we propose an inverse design algorithm (GOODBAP) which uses cascaded phase holograms to achieve arbitrary intensity distribution behind arbitrary aperture. The algorithm exploits a parallel optimization procedure based on numerical gradient, and the phase patterns on the two holograms are comprehensively updating using algorithmic differentiation. Multiple examples demonstrate that the GOODBAP algorithm can achieve high-fidelity (above 0.98) and high-diffractive-efficiency (above 0.98) intensity distributions behind seemingly unreasonable apertures. Furthermore, we expand the scope of this algorithm to cascaded modulation with more holograms. Also, an application is demonstrated about deceiving multiple cameras behind separate complex coded apertures. We expect that the GOODBAP algorithm can be applied to more practical scenarios of beam modulation, including laser imaging, illumination, annealing, etc.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0