Real-time phase-tracked dual-comb ranging with compact free-running dual-comb laser above 5kHz update rate

We report on an improved version of our real-time dual-comb LiDAR system for sub-micrometer positioning at long distances. Owing to a compact prototyped single-cavity dual-comb laser with improved low-noise performance combined with an updated GPU-accelerated processing algorithm, our system is capable of tracking the optical phase of the target in real time. Together with the time-of-flight based ranging, this enables enhanced relative precision when tracking targets across long distances. We test the system by continuously tracking a target moving over 40 m over several minutes. We discuss these and further improvements and investigate the trade-offs involved in designing such systems.