多纵模高光谱分辨率激光雷达马赫-曾德尔干涉仪的视场展宽技术  

Field-Widening Technique for Mach-Zehnder Interferometer in Multi-Longitudinal-Mode High-Spectral-Resolution Lidar

作　　者：高飞[1] 高丰佳 张锐 侯春 杨帆[1] 汪丽[1] 辛文辉[1] 李仕春[1] 华灯鑫[1] Gao Fei;Gao Fengjia;Zhang Rui;Hou Chun;Yang Fan;Wang Li;Xin Wenhui;Li Shichun;Hua Dengxin(School of Mechanical and Precision Instrument Engineering,Xi′an University of Technology,Xi′an 710048,Shaanxi,China)

机构地区：[1]西安理工大学机械与精密仪器工程学院,陕西西安710048

出　　处：《光学学报》2023年第6期261-269,共9页Acta Optica Sinica

基　　金：国家自然科学基金(42175149,41775035);中国-中东欧国家高校联合教育项目(202017);陕西省自然科学基金(2020JM-445)。

摘　　要：考虑到多纵模高光谱分辨率激光雷达(MLM-HSRL)接收的大气弹性散射回波具有与激光器发射光束一致的高斯传输特性,因此分析马赫-曾德尔干涉仪(MZI)光程差和透过率时必须要考虑发散角的影响。详细分析入射光束的发散角对大光程差MZI分光性能的影响,仿真计算得到基于空气腔的大光程差MZI所允许的光束发散角要≤0.4 mrad。为了降低发散角对大光程差MZI分光性能的影响,提出一种基于补偿玻璃的大光程差MZI的视场展宽技术。理论分析和仿真结果表明,视场展宽后系统可允许的发散角可达25.6 mrad,视场展宽技术极大地提升了大光程差MZI的分光能力。Objective Multi-longitudinal-mode(MLM)high-spectral-resolution lidar(HSRL)is a novel laser remote sensing technique for realizing fine detection of aerosol optical properties.The Mach-Zehnder interferometer(MZI)with a periodic transmittance is selected as the spectral discriminator for directly separating aerosol Mie scattering and molecular Rayleigh scattering spectra excited by the MLM laser.In principle,the design of the MZI for the application of the MLM-HSRL should meet two conditions.One is that the optical path difference of the MZI is twice the laser cavity length,and the other is that the optical path difference of the MZI is an integer multiple of the laser wavelength.The laser elastic echo scattering signal received by the MLM-HSRL has Gaussian transmission characteristics consistent with the laser beam,which makes the incident light beam on the MZI have a divergence angle.The divergence angle of the incident light beam leads to a deviation in the optical path difference of the MZI, which makes the optical path difference of the MZI fail toequal an integer multiple of the laser wavelength and then makes the discrimination capability of the MZI worse. As thedivergence angle of the incident light beam cannot be eliminated, a field-widening technique for the MZI with a largeoptical path difference based on compensated glasses is proposed to reduce the influence of the divergence angle of theincident beam on the discrimination capability of the MZI.Methods In this study, a field-widening technique for the MZI with a large optical path difference is studied for theapplication of the MLM-HSRL for realizing fine detection of aerosol optical characteristics. First, the required designparameters of the MZI with a large optical path difference and an inversion method of aerosol optical properties in theMLM-HSRL system are analyzed. Second, the mathematical relationship between the divergence angle of the incidentlight beam and the effective transmittance of the MZI with a large optical path difference is establi

关 键 词：测量 马赫-曾德尔干涉仪 多纵模高光谱分辨率激光雷达 视场展宽 大光程差 有效透过率 

分 类 号：TN958.98[电子电信—信号与信息处理]