The Design of All Fiber Laser Heterodyne Detection System

The traditional method of heterodyne detection is improved in this paper based on the principle of laser heterodyne detection.The laser heterodyne detection system is designed with all-fiber laser radar in all fiber system, and the laser, the optical system, the receiving device and so on are connected via the passive component.The system can mix the local oscillation light with signal light of measured object information in the photodetector surface, and the difference frequency signal is obtained.Then the signal is filtered and amplified by the signal processing technique to eliminate the DC component, and the desired difference frequency signal is obtained.Through the analysis of the performance of all fiber laser heterodyne detection system, the system has a strong ability to detect weak signal, high conversion gain and signal to noise ratio, and has a good filtering effect.The system is very suitable for the application of laser ranging and so on.