We demonstrate a tunable wavelength-locked seed laser source with high-frequency stability to realize the precise measurements of global atmospheric wind field. An Nd:YAG laser at 1 064 nm is used as the master laser (ML). Its frequency is locked to a confocal Fabry-Perot interferometer by using the Pound-Drever-Hall method, which ensures the peak-to-peak value of its frequency drifts less than 180 kHz over 2 h. Another Nd:YAG laser at 1 064 nm, as the slave laser, is offset-locked to the above ML using optical phase locked loop, retaining virtually the same absolute frequency stability as the ML. The tunable ranges of the frequency differences between two lasers are up to 3 GHz, and the tuning step length was an arbitrary integral multiple of 200 kHz. The researched seed laser source is compact and robust, which can well satisfy the requirement of the Doppler wind lidar.

报道了一种用于布里渊分布式光纤传感器(DOFS)的高稳定光学锁频系统。一台波长为1550 nm的半导体分布反馈(DFB)激光器作为主激光器用于光纤传感探测，另一台同样的激光器作为从激光器，采用光学锁相的方法将其与主激光器进行频率跟踪，使主激光器与从激光器频率差恒定为11 GHz。利用该光源搭建基于自发布里渊的分布式光纤传感系统(BOTDR)，可以有效地实现宽带移频，使得探测解调频率降低到百兆赫兹量级，大大降低了探测的噪声，并且降低了BOTDR系统成本。结果表明，采用此光源方案的频率波动范围为±1 MHz。