Laser is a kind of device which can emit laser and is one of the essential core components in modern laser processing system.With the development of laser processing technology, many new lasers are coming out.Because the laser has high brightness, good monochrome, good direction and coherence and other outstanding characteristics, so it is used in industry, agriculture, precision measurement and detection, communication and information processing, medical, military and other aspects, and caused a revolutionary breakthrough in many fields.Laser in the military in addition to communications, night vision, early warning, ranging and other aspects, a variety of laser weapons and laser guidance weapons have also been put into practice.