云南高美古湍流大气中激光短曝光光斑统计特性研究  

Statistical Properties of Short-Exposure Laser Patterns in Turbulent Atmosphere of Gaomeigu,Yunnan Province

作　　者：张骏昕 梅海平 沈刘晶 黄印博 罗福[5] 吴小龑 Zhang Junxin;Mei Haiping;Shen Liujing;Huang Yinbo;Luo Fu;Wu Xiaoyan(Key Laboratory of Atmospheric Optics,Anhui Institute of Optical and Fine Mechanics,Chinese Academy of Sciences,Hefei,Anhui 230031,China;Science Island Branch of Graduate School,University of Science and Technology of China,Hefei,Anhui 230026,China;Advanced Laser Technology Laboratory of Anhui Province,Hefei,Anhui 230037,China;Institutes of Physical Science and Information Technology,Anhui University Hefei,Anhui 230601,China;Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang,Sichuan 621900,China)

机构地区：[1]中国科学院安徽光学精密机械研究所中国科学院大气光学重点实验室,安徽合肥230031 [2]中国科学技术大学研究生院科学岛分院,安徽合肥230026 [3]先进激光技术安徽省实验室,安徽合肥230037 [4]安徽大学物质科学与信息技术研究院,安徽合肥230601 [5]中国工程物理研究院流体物理研究所,四川绵阳621900

出　　处：《中国激光》2021年第1期71-80,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金青年项目(11904369);中国科学院装备预研联合基金(6141A01130202);脉冲功率激光技术国家重点实验室主任基金(2019ZR07);安徽省自然科学基金青年项目(1908085QA37)。

摘　　要：为了探究激光在自由高空湍流大气中传输的短曝光光斑特性,在云南高美古3200 m的高海拔地区,选择远离下垫面的地势条件,开展了532 nm固体激光1,2,3,4,4.7 km大气传输光斑成像探测实验。利用4000 frame/s采样速率下的短曝光光斑数据,定性地描述了湍流大气中短曝光远场激光光斑的网纹状形态结构以及零星亮点的移动、消散和重构过程,并对激光光斑灰度值进行了定量的统计分析。结果表明:利用二维的光斑图像数据,可以较为方便地获得光强闪烁的孔径平均因子和理想的点闪烁指数,进而得到包括湍流强度和湍流内尺度在内的关键光学湍流参数;同时,也可对激光闪烁频谱、截止频率以及光斑的空间相关特性进行定量的判断。相关数据有助于研究高原或高空长程传输条件下的激光能量在目标靶面上的空间分布及其时间变化特性,为研究激光长程大气传输后光电系统的变化提供了一定的参考。Objective When laser propagates in the atmosphere,it is inevitable that a random change of the refractive index of the atmospheric turbulence causes laser spot broken and distorted,which seriously damages the laser beam quality.Under the conditions of weak-and strong-fluctuating media,the turbulence model has relatively rich theoretical research results.In view of the complexity of the turbulence itself,the current theory of light transmission in random media is not enough to perfectly present the far-field transmission characteristics of the laser spot in the strong-fluctuation region.As for the high-altitude laser transmission engineering applications,the spatial distribution of laser energy on the target surface and its temporal variation characteristics are vital for photoelectric system evaluation.However,the research of long-range high-altitude laser atmospheric transmission faces the following problems:first,there are few transmission tests in high-altitude areas;second,short-exposure laser spot data at high frame-rate sampling are rare;third,two-dimensional imaging methods to obtain more comprehensive laser statistical parameters are still lacking.In this study,we use a high-speed camera to perform laser spot tests at different distances in high-altitude areas.Using the laser short-exposure image data at sampling rate of 4000 frame·s-1,the change characteristics of short-exposure far-field laser spots in the turbulent atmosphere are qualitatively described,and the optical turbulence parameters such as ideal point scintillation indexes,aperture average factors,and inner scales are calculated.Our aim is to use the external field laser transmission test data to understand the spatial laser energy distribution on the target surface as well as its temporal variation characteristics under highaltitude conditions and to simultaneously determine its impact on the laser photoelectric system.Methods The experiment is performed at an altitude of 3200 m in Gaomeigu,far from the underlying surface.The transmitting te

关 键 词：大气光学 激光大气传输 光学湍流 短曝光 光斑图像 闪烁指数 

分 类 号：O436[机械工程—光学工程]