AOM and lock-in amplifier lidar-radar system for distance measurement

摘要

The lidar-radar architecture has been developed and used in detection and identification of targets in many domains. Basedon the single frequency monothilic NPRO (Nonplanar Ring Oscillator) and AOM (Acousto-Optical Modulator), a lidar-radar conceptive system for distance measurement has been constructed and investigated. The system consists of mainly three parts: the beat frequency laser source made up of NPRO and AOM, the transmitting and reflection collecting system and the lock-in amplifier signal processing unit. Then the distance measurement has been demonstrated using a 700-meter long single-mode fiber. In order to calculate unambiguously the actual distance, two synthetic frequencies have been introduced in turn. At last, using the lidar-radar setup, the displacement and velocity of a moving target which is mounted on a precise motorized optical bench have been displayed.