Simulation study on the laser range finder based on pseudorandom phase modulation and heterodyne detection

A laser range finder used the technique of heterodyne detection and pseudorandom phase modulation is proposed. The detail principle of the detection system is presented. Simulation results show that 34.6 dB signal to noise ratio can be achieved under the laser transmit power of 0.1W, pulse length of 82us, telescope aperture of 0.1m, local oscillator power of 1mW, target distance of 100m. And the system possesses 10dB advantage in system sensitivity compared with the system utilizes the pseudorandom intensity modulation combined with single photon detection.