Adopt phase modulator's dualbeam laser doppler velocity measurement system

The utility model belongs to the optics field discloses an adopt phase modulator's dualbeam laser doppler velocity measurement system, the tachymeter includes: infrared semiconductor laser, ruddinessindicate semiconductor laser, the coupler, and phase modulator, a collimating lens, the 2nd collimating lens, the receiver lens, infrared light detector, wherein, infrared semiconductor laser and ruddiness instruct semiconductor laser respectively through the fiber connection the one end of coupler, the other end of coupler is through the fiber connection phase modulator, phase modulator falls into even two the tunnel with the infrared laser of conduction to respectively through fiber optic conductor extremely a collimating lens and the 2nd collimating lens front end, the light that reflects through moving object is focused on to infrared light detector by the receiver lens. The utility model provides an original adoption reputation frequency shifter move the system technology complicacy that tests the speed, the