将结合外调制技术与主从式注入锁定技术的方法用于获得宽带线性调频光源,并基于该光源实现了同时测距和测速的调频连续波激光雷达系统。主从式注入锁定系统包含作为主激光器的窄线宽光纤激光器和作为从激光器的分布反馈式半导体激光器,它们的输出波长均约为1550 nm;使用频率范围为8~14 GHz的三角波线性调频微波对主激光器进行调制,调制后的光注入到从激光器,获得了6 GHz带宽、超过20 dB边模抑制比的宽带线性调频光源。基于该光源搭建了调频连续波激光雷达系统,采用该系统实现了对静态物体距离、运动物体瞬时距离与瞬时速度的测量,运动物体的距离和速度测量结果由不同的公式获得并可以相互验证,实现的距离和速度分辨率分别为2.5 cm和7.8 mm/s。

This paper proposes a method combining external modulation technology and master-slave injection-locking technology to obtain a broadband linear-chirped laser source, and the laser source is used to realize a frequency modulated continuous wave light detection and ranging (LIDAR) system for simultaneous distance and speed measurement. The master-slave injection-locking system includes a narrow line-width fiber laser as the master laser and a distributed feed-back (DFB) semiconductor laser as the slave laser, and their wavelengths are both about 1550 nm. A triangular linear-chirped microwave signal with a frequency range of 8--14 GHz is used to modulate the output from the master laser, and then the modulated laser is injected into the DFB semiconductor laser to obtain a broadband linear-chirped laser with a 6 GHz bandwidth and a side-mode suppression ratio over 20 dB. We build a frequency modulated continuous wave LIDAR based on the laser source. Using this system, we perform the distance measurement of static objects and the instantaneous measurement of distance and speed of a moving object. The distance and speed of a moving object are obtained by different formulas and verified with each other. The distance and speed resolutions are 2.5 cm and 7.8 mm/s, respectively.