Research on CO 2 laser radar imaging experiment

The laser radar is a radar system adopting laser photosource and operating on optical band and the laser heterodyne measurement is a detection technique with high sensitivity. Optical system plays an important role in heterodyne detection system. The reasonable selection of performance parameters of optical system has direct influence upon the ability of system to detect objects. The characteristics of the receiver and the transmitter are discussed in this paper. In order to make the diffraction disk matching the detector size, the laser beam are confined and made the beam divergence angle of the transmitter equal to the receiver angle determined by antenna theory. In order to transmit laser to target's surface and receive the echo from the target efficiently, each optical parameter of the detective system must accord with the coherent condition. The CO2 laser coherent imaging radar system established by us can get the photo-quality imaging of the target and it has wide application foreground. Primary parameters including beam expander's clear aperture, beam divergence angle, the focus of system etc and calculating examples were given to show how to determine the parameter of optical system and realize these purposes.