1 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室及超强激光科学卓越中心，上海 201800
2 中国科学院大学材料与光电研究中心，北京 100049
飞秒强激光脉冲在大气中传输时，会形成狭长的、具有高激光强度、高等离子体密度、可远程产生和操控的通道，即光丝。光丝与物质相互作用时，高激光强度可激发物质辐射具有指纹特征的荧光谱线，成丝过程可产生覆盖整个大气光学传输窗口的超连续谱激光，通过光学差分吸收实现多组分大气成分的检测分析。飞秒强激光非线性成丝为多相态、多组分大气遥感提供了新的技术途径。主要围绕飞秒激光大气成丝远程诱导击穿光谱技术和光丝超连续谱激光雷达技术两种基于飞秒激光的大气遥感新技术，综述了两种技术的原理、光谱测量和分析方法及其相关研究进展，分析了飞秒强激光大气遥感应用存在的关键科学和技术问题并对未来发展进行了展望。
大气光学 大气环境监测 飞秒激光成丝 光丝诱导击穿光谱 白光激光雷达 超连续谱 激光与光电子学进展
2022, 59(7): 0700001
Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3 Department of Physics, College of Arts and Science, University of Colorado Boulder, Boulder, CO 80309, USA
4 College of Physics, Guizhou University, Guiyang 550025, China
5 Department of Physics, Shanghai Normal University, Shanghai 200234, China
6 Physics Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
Laser polarization and its intensity inside a filament core play an important role in filament-based applications. However, polarization dependent clamping intensity inside filaments has been overlooked to interpret the polarization-related filamentation phenomena. Here, we report on experimental and numerical investigations of polarization dependent clamping intensity inside a femtosecond filament in air. By adjusting the initial polarization from linear to circular, the clamping intensity is increased by 1.36 times when using a 30 cm focal length lens for filamentation. The results indicate that clamping intensity inside the filament is sensitive to laser polarization, which has to be considered to fully understand polarization-related phenomena.
femtosecond laser filamentation clamping intensity polarization Chinese Optics Letters
2021, 19(10): 103201
Author Affiliations
Abstract
1 MOE Key Laboratory of Advanced Micro-structured Materials, Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
2 State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
4 Science and Technology on Space Physics Laboratory, Beijing 100076, China
We report on a simultaneous generation of double white light lasers through filamentation by focusing a femtosecond laser pulse. The appearance of the two white light lasers can be controlled by tilting the focusing lens. The spectral bandwidth and the pulse energy of the double white light lasers were controlled by tuning laser filamenting pulse energy and polarization. Two white light lasers with pulse energies of 1.54 mJ and 1.84 mJ, respectively, were generated with the pump laser energy of 7.43 mJ. Besides being beneficial in understanding the multiple white light lasers generation process through multiple filamentation and its control, the results are also valuable for white light laser-based applications.
filamentation white light laser polarization Chinese Optics Letters
2020, 18(12): 121402
1 中国科学院上海光学精密机械研究所强场激光物理国家重点实验室, 上海 201800
2 中国科学院大学材料与光电研究中心, 北京 100049
研究了飞秒激光成丝过程中钳制光强对脉宽的依赖关系。对不同脉宽成丝钳制光强进行直接实验测量,发现当脉宽逐渐展宽(由45 fs展宽至177 fs)时,对应的钳制光强逐渐减小。实验结论与通过求解非线性薛定谔方程得到的数值模拟结果一致。依赖于脉宽的钳制光强的分析结果可为深入理解与脉宽相关的光丝应用提供科学依据和新思路。
激光器 飞秒现象 飞秒激光成丝 钳制光强 啁啾
中国洛阳电子装备试验中心, 河南 洛阳 471003
激光制导**半实物仿真中通过对激光能量精确控制, 来逼真模拟战场环境下激光导引头接收到的激光能量。需要对激光能量模拟误差进行分析研究, 以保证半实物仿真的可信度。重点分析了半实物仿真中激光信号传输的全过程, 给出了激光信号传输各环节引起的能量控制不确定度; 提出了激光能量密度模拟误差模型和误差分析方法, 举例说明了该误差分析方法的具体应用, 并设计实验验证了模型准确性。根据误差分析模型, 可有效评估激光能量密度模拟误差, 优化仿真想定设计, 保证半实物仿真结果精度。
半主动激光制导** 半实物仿真 激光能量 误差 semi-active laser guided weapon hardware-in-the-loop simulation laser energy error 红外与激光工程
2018, 47(10): 1006005
Author Affiliations
Abstract
1 Department of Physics, Shanghai University, Shanghai 200444, China
2 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 Centre d’Optique, Photonique et Laser (COPL) and Département de physique, de génie physique et d’optique, Université Laval, Québec, Québec G1V 0A6, Canada
We report on a systematic study of the laser polarization effect on a femtosecond laser filamentation in air. By changing the laser’s ellipticity from linear polarization to circular polarization, the onset position of laser filament formation becomes farther from the focusing optics, the filament length is shorter, and less laser energy is deposited. The laser polarization effect on air filaments is supported by a simulation and analysis of the polarization-dependent critical power and ionization rates in air.
320.2250 Femtosecond phenomena 260.5430 Polarization Chinese Optics Letters
2018, 16(7): 073201
Author Affiliations
Abstract
1 State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Shanghai University, Shanghai 200444, China
We demonstrate a simple technique to filter out the continuum background in filament-induced remote breakdown spectroscopy. By inserting a polarizer before the detector, the continuum background was reduced by more than 42% in filament-induced breakdown spectroscopy at a distance of 3.8 m, while the fluorescence intensity of aluminum atomic lines remains constant. Supercontinuum through self-phase modulation during filamentation mainly contributes to the continuum background. The polarization-gated technique provides a simple way to remove the continuum background in filament-induced remote breakdown spectroscopy.
120.0280 Remote sensing and sensors 260.5430 Polarization 300.6365 Spectroscopy, laser induced breakdown Chinese Optics Letters
2018, 16(3): 033201
中国海洋大学光学光电子实验室, 山东 青岛 266100
针对钢铁合金样品中存在基体效应复杂的问题, 通过优化支持向量机模型的输入特征, 建立多元素变量的定量分析模型, 预测钢铁合金样品中Cr和Ni元素的含量。 研究结果表明, 分别以特征谱线的峰值强度和积分强度作为支持向量机模型的输入时, 积分强度因为包含了谱线的谱宽和形状信息, 模型训练效果较好; 相比于单一元素谱线的特征信息, 采用多元素的多条谱线信息输入支持向量机模型时, 模型训练效果较好, 这是由于多种谱线信息的输入可以有效校正基体效应的影响。 在此基础上, 通过归一化变量将内标法与多变量定标方法有效结合, 不仅可以减小实验测量误差还能有效校正基体效应的影响, 而且有效提高了模型的重复率和准确率。 归一化变量作为支持向量机模型的输入变量, 对待测样品S1和S2中Cr元素含量预测的相对误差为6.58%和1.12%, 对Ni元素浓度预测的相对误差为13.4%和4.71%。 通过归一化变量将内标法与多变量定标方法有效结合, 可以充分发挥SVM算法的非线性学习优势, 为LIBS技术应用于复杂样品定量定标分析提供理论基础。
支持向量机(SVM) 激光诱导击穿光谱 基体效应 钢铁合金 Support vector machine (SVM) Laser induced breakdown spectroscopy Matrix effect Steel Alloy 光谱学与光谱分析
2016, 36(7): 2244
1 中国洛阳电子装备试验中心, 洛阳 471003
2 中国航空工业集团公司 洛阳电光设备研究所, 洛阳 471000
为了对复杂背景光条件下激光告警设备进行效能评估, 基于不同阳光背景开展了激光告警概率曲线的相关研究。首先, 对激光告警设备面临的复杂背景光进行了分析; 其次, 通过理论研究和实验验证, 初步获得了激光告警设备在不同强度阳光背景下告警概率曲线变化规律; 最后, 提出了一种由典型阳光背景下告警概率曲线测试结果推算到不同阳光背景下告警概率曲线的方法。结果表明, 阳光背景辐射严重影响着激光告警设备的性能, 告警阈值随着阳光辐照强度的增加而增加,告警灵敏度下降。此研究结果有助于进一步提高激光告警设备评估能力。
激光技术 激光告警 概率曲线 阳光背景 laser technique laser warning probability curve background sunlight
针对近地面来袭的激光威胁源, 建立基于米氏散射理论的散射探测模型。利用matlab软件对散射光光强随激光探测方向、大气能见度的变化进行了数值分析, 结果表明, 探测散射光最强的方向是平行于主轴传输方向, 大气能见度和散射光强成非线性关系。在分析散射光强受气象条件变化的基础上, 得到了不同激光威胁源情况下, 激光告警的最大散射截获距离。
激光告警 散射探测 散射截获距离 大气能见度 laser warning scattering detection scattering interception range atmospheric visibility
