摘要
为了实现光丝激光雷达系统的天基应用,开展了天基光丝雷达光谱仪光学系统设计,根据应用需求确定光谱仪光学系统构型主要由望远系统、狭缝、准直系统、平面光栅、成像系统构成;为了解决谱段宽可能引入的色差问题,光谱仪系统采用全反射结构设计;完成了光学系统与各项指标分析,通过设计可达到以下指标:光谱仪谱段范围为320~950 nm,光谱分辨率为2 nm,光谱仪最大色畸变为1.1μm(即0.07 pixel),3个像元内的能量集中度大于96%,光学传递函数MTF在3.7 lp/mm下可达到0.99。所设计的光谱仪系统可用于星载大气成分高分辨率光谱探测。
Objective With the development of ultrashort and ultra-intense laser,it has been revealed that when a femtosecond laser pulse propagates in air,filaments,referred to as “filament laser”,would occur owing to nonlinear effects.Traditional spaceborne airpollution monitoring devices rely on spectral imaging and LiDAR technology,which cannot realize real-time monitoring of atmospheric multi-component pollutants,identify unknown pollutants,and detect the chemical composition of various pollutants.The filament laser system in orbit emits a femtosecond laser pulse into the atmosphere,and the intensity of the femtosecond laser pulse is sufficient to ionize molecules in the atmospheric environment.Ionization excites the fluorescence spectrum carrying the information of the material composition,which can determine the various material components,species,and content in the area of the filament laser.To aid the research on space-based filament lidar technology,this study explored the optical system design of a space-based filament lidar spectrometer for remote sensing applications and realized the optical system configuration design.The spectral range and resolution of the spectrometer are 320-950 nm and 2 nm,respectively,and it has applicability in high resolution spectral detection of atmospheric pollutant composition.Methods First,the application requirements of space-based filament lidar spectrometer were analyzed.On the basis of the characteristics of pollutants and the corresponding spectra of the substance elements,the working spectrum of the spectrometer and the spectral resolution were designed to be 320-950 nm and 2 nm,respectively.Using filament laser propagation simulation software,the filament laser diameter was found to be approximately 6 mm after 400 km orbital propagation.The filament laser diameter can be constrained to a small spatial scale after ultralong-distance propagation.To conform to the spectral range and resolution requirements,the size of CCD detector is 1024×1024,with 13 μm×13 μm pixel siz
作者
刘晓林
刘勋
李维
张庭成
孙德伟
张丽
蔺宇辉
Liu Xiaolin;Liu Xun;Li Wei;Zhang Tingcheng;Sun Dewei;Zhang Li;Lin Yuhui(Beijing Institute of Space Mechanics&Electricity,Chinese Academy of Space Technology,Beijing 100094,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2023年第7期131-137,共7页
Chinese Journal of Lasers
基金
国家重点研发计划(2018YFB0504400)。
关键词
光学设计
光丝激光
光谱仪
光学系统设计
光谱分辨率
optical design
filament laser
spectrometer
optical system design
spectral resolution
