In recent years, laser technology has been developed rapidly and is familiar to people. Its application fields mainly include industrial manufacturing, national defense, communications, medical beauty, consumer entertainment, etc.For different fields, scenes, laser wavelength, power, beam, intensity, pulse width and other properties are not the same, in reality, few people will understand the performance parameters of the laser.At present, the laser can be divided into crystal luminescent solid state laser, gas laser, fiber laser, semiconductor laser, chemical liquid laser and so on.