双波长高光谱分辨率激光雷达光谱鉴频器设计

Design of Dual-Wavelength Spectral Discriminator for High-Spectral-Resolution Lidar

提出了一种可作为高光谱分辨率激光雷达(HSRL)光谱鉴频器的双波长视场展宽迈克耳孙干涉仪(FWMI)的设计方法。详细阐述了双波长FWMI的设计原理,权衡考虑色散对于鉴频性能的影响。通过双波长视场展宽设计实现折射率补偿,从而使FWMI在355 nm和532 nm均有较大的接收视场。给出适用于355 nm和532 nm的双波长FWMI设计的具体参数,并对其进行性能评估和容差分析。评估结果表明,双波长FWMI拥有超过6°的接收视场角,在两个波长均有较为优异、稳定的性能表现,对于加工和装配精度要求也并非苛刻。利用蒙特卡罗仿真对基于双波长FWMI的HSRL系统的光学参数的反演误差进行分析。分析结果表明,在532 nm,气溶胶后向散射系数和消光系数的反演误差分别为1.82%和11.39%,而在355 nm,二者分别为1.62%和2.95%。

A design method of a dual-wavelength field-widened Michelson interferometer(FWMI)used as a spectral discriminator of a high-spectral-resolution lidar(HSRL)is proposed.The theoretical principle of the dual-wavelength FWMI is elaborated in detail.The influence of dispersion on the frequency discrimination performance is considered.The dual-wavelength field-widened design is adopted to compensate for refractive index,so that FWMI has a larger receiving field of view at 355 nm and 532 nm.The specific parameters of the dual-wavelength FWMI suitable for 355 nm and 532 nm are given,and performance evaluation and tolerance analysis are carried out.The evaluation results show that the dual-wavelength FWMI has a receiving field of view of more than 6°and excellent and stable performance at both wavelengths,and the requirements of processing precision and assembly precision are not high.Finally,Monte Carlo simulation is used to analyze the inversion error of optical parameters of the HSRL system using the dual-wavelength FWMI.The results show that the retrieval errors of aerosol backscattering coefficient and extinction coefficient are 1.82%and 11.39%at 532 nm,and 1.62%and 2.95%at 355 nm,respectively.