High Sensitivity Ranging Photon-counting Chirped Amplitude Modulation Lidar

Traditional lidar is not effective in detecting small long-range targets with weak echo signals. Geiger-mode Avalanche Photodiode (Gm-APD) single photon detector has super high sensitivity. By adding photon orbital angular momentum modulation module, a photon-counting chirped amplitude modulation lidar with high sensitivity ranging function is designed. Based on the characteristics of photon orbital angular momentum space transmission, a special demodulation method is used to realize the spatial separation of noise and signal. The above scheme achieves the goal of high sensitivity ranging detection. The simulation results show that the scheme can improve the signal-to-noise ratio of the system effectively and realize the high-sensitivity ranging function of small target in long distance.