采用温控和碘吸收池技术的发射激光稳频技术

多普勒测风激光雷达通过分析系统回波信号的多普勒频移反演出风速，为提高风场探测精度，从稳频技术方面展开研究。在稳频过程中，分别采取措施消除激光频率的长期漂移和短期抖动。针对激光频率的长期漂移，设计并研制了种子激光器温控箱，通过水浴的控温方式大大减小了激光频率的长期漂移，将激光频率稳定在±50 MHz以内；针对激光频率的短期抖动，采用以碘分子吸收池为核心器件的稳频系统，通过半导体控温方式对碘分子吸收池精确控温，控温精度达0.03 ℃，提高了稳频精度，将激光频率进一步稳定在±8 MHz以内，满足±10 MHz以内的设计精度要求。通过搭建多普勒测风激光雷达系统，对发射激光稳频装置进行系统验证，连续4组风场观测结果表明:系统探测高度为17 km，绝大部分方差在4 m/s以下，满足测风激光雷达测量指标的要求。

Laser frequency stabilization technology using temperature control and iodine absorption cell technology

Doppler wind measurement lidar reverses the wind speed by the Doppler frequency shift of the echo signal of the system.In order to improve the detection accuracy of the wind field,the research was carried out from the aspect of frequency stabilization technology.During the frequency stabilization process,measures were taken to eliminate the long-term drift and short-term jitter of the laser frequency.For the long-term drift of the laser frequency,a temperature control box for the seed laser was designed and developed,which greatly reduced the long-term laser frequency shift by controlling the temperature of the water bath.The laser frequency was stabilized within±50 MHz.For short-term jitter of the laser frequency,a frequency stabilization system with an iodine molecular absorption cell as the core device was adopted to accurately control the temperature of the iodine molecular absorption cell through semiconductor temperature control,with a temperature control accuracy of0.03℃,the frequency stabilization accuracy was improved,and the laser frequency was further stabilized within±8 MHz to meet the design accuracy requirements within±10 MHz.Through the establishment of Doppler wind measurement lidar system,the launching laser frequency stabilization device was verified.The observation results of 4 consecutive sets of wind field show that the detection height of the system was 17 km,and most of the variances were below 4 m/s.It meets the requirements of wind lidar measurement indicators.