钠多普勒激光雷达通过发射单模窄线宽的589 nm脉冲激光, 激发80~110 km高度大气中存在的碱金属钠原子获得共振荧光散射回波信号, 可实现中层顶区域大气参数的探测。激光稳频和移频是窄带钠多普勒激光雷达实现中层顶大气风场和温度高分辨探测的关键技术。本文介绍了一种应用于钠激光雷达系统的种子激光稳频和移频方法, 利用归一化的饱和吸收光谱信号实现了589 nm种子激光频率的精确锁定, 频率长期稳定在2.2 MHz左右; 通过级联双通声光移频装置的设计获得了钠原子D2线光谱上三个工作频率的窄线宽激光输出。通过钠多普勒激光雷达的探测实验, 获得了高分辨率的钠层风场和温度探测结果, 并将温度探测结果与卫星探测结果进行了对比。

The sodium lidar can achieve atmospheric parameters measurement in the mesosphere by emitting a single-mode narrow-linewidth 589 nm pulsed laser to stimulate the alkali metal sodium atoms in the atmosphere at 80-110 km altitude and obtain the resonance fluorescence scattering echo signal. Laser frequency stabilization and shifting are the key technologies for the narrow-band sodium Doppler lidar to realize mesosphere atmosphere wind and temperature detection with high resolution. This paper introduces the methods of seed laser frequency stabilization and shifting applied in a sodium lidar system. The precise locking of 589 nm seed laser frequency is achieved using the normalized saturation absorption spectrum signal, and the long-term stability of laser frequency is about 2.2 MHz; three laser operating frequencies on the sodium D2 line spectrum are obtained by designing a cascaded double-pass acousto-optic frequency shift device. Through the experiment with sodium Doppler lidar, the wind and temperature measurement results with high resolution are obtained, and the temperature profile from lidar is compared with the result measured by satellite.