2.2 km Ranging Based on Hybrid Integrated FMCW Laser

We report a long-distance detection experiment based on our proposed ultra-narrow linewidth frequency-modulated continuous wave laser. The laser is a hybrid integrated laser working under self-injection locked state by coupling semiconductor laser to an external high-Q cavity. The laser operates at 1 kHz chirped frequency with 6.6 GHz modulated frequency range. The intrinsic linewidth is less than 20 Hz and the modulated linearity 1 - r(2) is optimized to 10(-6). In the 2.2 km ranging experiment, we get the signal-to-noise ratio of the detected signal higher than 5 dB with a amplified output power of 100 mW and expanded beam diameter of 15 mm. The mean value of the demodulated distance is 2209 m, and the standard deviation is 0.67 m. This is the first demonstration of the application of hybrid integrated lasers for long-range detection, verifying the application of narrow linewidth FMCW laser in LiDAR is system.