Author Affiliations
Abstract
1 School of Electronics and Information, Guangdong Polytechnic Normal University, Guangzhou 510665, China
2 Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, South China Normal University, Guangzhou 510006, China
3 Guangzhou Key Laboratory for Special Fiber Photonic Devices, South China Normal University, Guangzhou 510006, China
4 Guangdong Provincial Key Laboratory of Industrial Ultrashort Pulse Laser Technology, Shenzhen 518055, China
In this work, we demonstrated the double-cladding Tm/Al co-doped photonic crystal fiber (PCF) by laser additive manufacturing. The measurements show that the fiber was heavily doped with a concentration of 2.13% (mass fraction) without any crystallization. The splicing property of PCF was studied, and the integrity of the PCF air holes was maintained during the splicing process. The PCF with combiner pigtail has a splice loss of 0.23 dB. The all-fiber Tm/Al co-doped PCF amplifier system achieves a slope efficiency of 13% at 1948 nm with an output laser power of nearly 1.59 W. An upconversion process was also observed under laser excitation with a 1064 nm pulse. This method provides a new idea to deal with Tm-doped PCF fabrication and promotes the promising application of 2 µm fiber lasers.
photonic crystal fiber laser laser amplification Chinese Optics Letters
2023, 21(12): 121401
空地协同作业场景中要求无人机同时具备快速路径规划与精准自主降落功能, 这对无人机搭载有限计算资源下算法的实时性和准确性提出了更高要求。主要解决了无人机快速路径规划与自主降落功能一体化实现关键技术难题。首先, 针对传统A*算法实时性差、消耗资源多等问题, 将传统8邻域搜索方式改进为16方向搜索方式, 并设计高匹配度启发函数和自适应权重系数全面提升路径规划算法性能; 其次, 设计了基于视觉反馈的面向空地协同作业场景下无人机自主降落策略, 提高了自主降落的精度; 最后, 进行了仿真和实验,验证了所提改进A*算法、自主降落和一体化实现策略的性能。结果表明, 改进的A*算法在规划路径长度与平滑度性能方面均得到提升, 算法实时性大幅提升, 满足复杂环境下的实时避障与规划需求;同时, 无人机可以快速稳定地降落在地面平台目标点上。
空地协同 无人机 路径规划 改进A*算法 自主降落 air-ground collaboration UAV path planning enhanced A* algorithm autonomous landing
1 华南师范大学广州市特种光纤光子器件与应用重点实验室, 广东 广州510006
2 广东省工业超短脉冲激光技术企业重点实验室, 广东 深圳 518055
3 华南理工大学化学与化工学院, 广东 广州510641
4 广东省计划生育科学技术研究所(广东省计划生育专科医院), 广东 广州510600
传统的陶瓷成型工艺存在着材料利用率低、能量消耗高等问题。为此, 本文利用数字光处理(DLP)3D打印技术, 制备了精细、复杂结构氧化锆陶瓷。实验配置了固相质量分数72.5%的陶瓷-光敏树脂浆料, 以紫外光为光源, 使浆料逐层固化, 叠加成型。实验还研究了曝光时间、曝光强度等因素对固化深度的影响, 优化后的陶瓷浆料表现出良好的固化效率与成型精度。最后本文还研究了烧结温度对陶瓷器件致密度以及维氏硬度的影响。最终制造出了致密度达95%以上、维氏硬度11.3 GPa、XRD表征为四方相的氧化锆陶瓷器件, 实现了复杂陶瓷器件的快速打印制备。
陶瓷材料 光敏树脂 数字光处理 烧结 ceramic material photosensitive resin DLP sintering
Author Affiliations
Abstract
1 Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, South China Normal University, Guangzhou 510006, China
2 Guangzhou Key Laboratory for Special Fiber Photonic Devices, South China Normal University, Guangzhou 510006, China
3 Guangdong Provincial Key Laboratory of Industrial Ultrashort Pulse Laser Technology, Shenzhen 518055, China
In this work, we proposed a feasible method to prepare the Bi/Al co-doped silica glass by using laser additive manufacturing technology. Bi was uniformly doped into the silica matrix. The hydroxyl content of the glass sample was measured to be 29.36 ppm. Using an 808 nm laser diode as the excitation source, a broadband near-infrared emission from 1000 to 1600 nm was obtained. The emission peak was centered at 1249 nm, and the corresponding FWHM was more than 400 nm. The results show that the laser additive manufacturing technology is promising to fabricate highly homogeneous Bi-doped core materials with broader emission band, which is beneficial to solving the communication capacity crunch and promotes the development of fiber communication in the upcoming fifth and sixth generation systems.
optical materials bismuth-doped glass broadband fluorescence Chinese Optics Letters
2020, 18(12): 121601
Nan Zhao 1,2Jiaming Li 1,2,3,*Qiongxiong Ma 1,2,3Liang Guo 1,2,3Qingmao Zhang 1,2,3
Author Affiliations
Abstract
1 Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, South China Normal University, Guangzhou 510631, China
2 Guangzhou Key Laboratory for Special Fiber Photonic Devices, South China Normal University, Guangzhou 510631, China
3 Guangdong Provincial Key Laboratory of Industrial Ultrashort Pulse Laser Technology, Shenzhen 518055, China
Carbon is hard to be sensitively detected in laser-induced breakdown spectroscopy (LIBS). The optical emission can be significantly enhanced by resonantly exciting CN radicals in the plasma center using LIBS assisted with laser-induced fluorescence (LIBS-LIF). However, the nitrogen source for CN formation is provided by ambient gas. Therefore, we propose a new approach of periphery excitation in plasma to improve CN fluorescence. The optical and spatial characteristics of CN radicals in plasma were discussed. A fluorescence map was established by combining focal point location and fluorescent intensity, demonstrating that plasma periphery had 4.2 times stronger fluorescence than the center.
laser-induced breakdown spectroscopy laser-induced fluorescence carbon Chinese Optics Letters
2020, 18(8): 083001
1 上海交通大学 物理系, 上海200240
2 清华大学 物理系, 原子分子纳米科学教育部重点实验室, 北京 100084
如何人为地诱发同核异能态辐射，从而利用储存在其中的巨大能量，是个备受关注的交叉学科课题。利用原子物理过程进行触发是目前较为可行的方案，原子物理参数将在里面起到关键作用。介绍了一套高效率的原子数据库，目前该数据库可对原子序数小于９６的元素所有电离度离子的能级结构信息进行快速扫描，从而筛选出一些可能通过原子过程触发的同核异能态体系。通过在197Au元素电子跃迁诱导核激发过程和178Hf元素电子俘获诱导核激发过程中的应用,展示了该数据库对寻找合适同核异能态体系的作用。isomer triggering via nuclear excitation
同核异能态 γ射线激光 原子数据 电子跃迁诱导核激发 电子俘获诱导核激发 isomer gamma ray laser atomic data nuclear excitation by electronic transition nuclear excitation by electron capture
1 上海交通大学 物理系,上海 200240
2 清华大学 物理系 原子分子纳米科学教育部重点实验室,北京 100084
介绍了同核异能态的特点和诱发同核异能态的几种机制,如直接光激发、电子跃迁诱导核激发(NEET)和电子俘获诱导核激发(NEEC)。同核异能态的诱发辐射研究目前在国际上竞争激烈,尤其是对最近提出的NEEC的研究。同时探讨了在我国开展这些研究的可能性。
同核异能态 γ射线激光 直接光激发 电子跃迁诱导核激发 电子俘获诱导核激发 isomer γ ray laser direct photon excitation nuclear excitation by electronic transition nuclear excitation by electron capture
中山大学 光电材料与技术国家重点实验室,广东 广州 510275
对高精度激光光路自动准直系统,提出了一种更加精准的四象限探测器的信号处理算法,采用四象限硅光电二极管代替传统的CCD探测光线指向,运用DSP技术处理探测信号,控制惯性压电陶瓷电动调节架快速自动准直,精度可达1μrad。该系统很好地解决了传统的CCD探测光线方法中的处理速度慢、校正精度低、占用资源大的问题。飞秒激光实验应用证明,系统能够实现激光光路的快速自动准直。
四象限光电二极管 惯性压电陶瓷 激光准直 four-quadrant photodiode inertial piezoelectric ceramics laser collimation
