532 nm多普勒激光雷达中F-P标准具的优化设计

Fabry-Perot标准具是532 nm多普勒测风激光雷达的核心部件，其参数和加工精度直接影响整个系统的灵敏度和风速测量的精度。对不同波长的回波信号进行模拟，分析所选测量激光波长532 nm的原因。通过对系统的灵敏度和测量精度进行分析，优化设计标准具的主要参数，分析认为，标准具的自由光谱区为9 GHz，带宽1.75 GHz，两边缘通道峰值间隔4 GHz，锁定通道与边缘通道峰值间隔为1.125 GHz时，系统的灵敏度和测量精度最优。通过模拟计算标准具的主要缺陷对透过率的影响，确定标准具的表面加工精度要求5 nm，平行调节时腔长的最大差值要求小于10 nm。

Design and Optimization of Fabry-Perot Etalon in 532 nm Doppler Lidar

As the core elementof a 532 nm Doppler lidar, Fabry-Perot etalon has direct effects on the velocity sensitivity and measurement precision. The reason of selecting 532 nm as the laser wavelength was analyzed by simulating the received signal. Optimizations of the free spectral range, full width at half maximum and peak value interval in three channels were presented by analyzing the velocity sensitivity and relative error. 9 GHz is selected as the free spectral range, and 1.75 GHz as the full width at half maximum, 4 GHz and 1.125 GHz as the interval between two edge channels and between the edge channel and locking channel respectively. The precision during processing and parallelism adjusting during experiment of the etalon was analyzed by simulating effects on the transmission of the main defects. 5 nm of processing precision and 10 nm of the maximal difference of the etalon spacing are required in the system.