Gas laser features in simple structure, low price, easy operation, uniform working medium, high-quality beam as well as prolonged, stable, and continuous operation. It is also a type of laser of diversified varieties and extensive applications with a market share of up to 60% approximately. Wherein, He-Ne laser is the most universal one.

Diode laser takes semiconductor material as a working medium. Presently, relatively well-established ones include gallium laser that emits 840nm laser. Furthermore, there are also gallium arsenide, chromium sulfide, and zinc sulfide lasers with the addition of aluminum. Excitation modes include optical pump, electric excitation, and so on. Such lasers feature in small volume, lightweight, long service life as well as a simple and solid structure, which are especially applicable to aircraft, vehicles, and spacecraft. The development of optical fiber-based communication and disc technologies at the end of the 1970s has greatly promoted the development of diode lasers.

The universal one is a dye laser that uses an organic dye as the working medium. In most cases, an organic dye is dissolved into solvents (ethanol, acetone, water, etc) for application in vapor form. It is obtained laser of different wavelength (within visible range) by using different dyes. Dye laser normally uses a laser as pump source, for instance, argon-ion laser and so on.