多普勒激光雷达中种子激光注入的一种鉴别方法

多普勒测风激光雷达以其高分辨率、高精度、大探测范围、能提供三维风场信息的能力，吸引了多国学者的关注，并投入了大量的人力、物力进行研究。所研究的多普勒测风激光雷达采用种子注入的方式获得单纵模、窄线宽、高功率的激光输出。激光器中心频率的缓慢漂移、环境噪音、激光棒温度变化或者振动干扰都有可能导致激光器种子光的注入不成功，出射激光光谱由注入成功时的单纵模输出变为多纵模输出。激光单纵模输出时线宽约为200 MHz，而多纵模时激光线宽很宽。而种子注入不成功时所出射的多纵模激光脉冲将导致瑞利后向散射谱变宽，会增加风速测量误差。该脉冲筛选电路在数据采集环节实现对多纵模激光脉冲的筛选，有效降低了风速测量误差，提高测风准确度。

An identification method of seed laser injection in Doppler lidar

Doppler wind lidar with its high resolution, high precision, large detection range, the ability to provide three-dimensional wind field information, has attracted the attention of multinational scholars, and put a lot of manpower and material resources to carry out research. The Doppler wind lidar was designed to obtain single longitudinal mode, narrow linewidth and high power laser output by seed injection. The slow drift of the center frequency of the laser, ambient noise, laser rod temperature change or the vibration disturbance may cause the failure of seed injection. Then the laser spectrum was transformed from a single longitudinal mode output to a multiple longitudinal mode output. The linewidth of single longitudinal mode laser output was about 200 MHz. However, the multi-longitudinal mode laser output had a wide linewidth,which led to widened Rayleigh backscattering spectrum and then great speed errors in the speed inversion condition. The pulse screening circuit was developed to filter the multi longitudinal mode pulse during the data acquisition, which can effectively reduce the error of wind speed inversion and improve the precision of wind speed measurement.