Gas Lasers

The laser medium of a gas laser can be a pure gas, a mixture of gases, or even metal vapour usually contained in a cylindrical glass or quartz tube. Two mirrors are located outside the ends of the tube to form the laser cavity. Gas lasers are pumped by ultraviolet light, electron beams, electric current, or chemical reactions. The helium-neon laser is known for its high frequency stability, color purity, and minimal beam spread. Carbon dioxide lasers are very efficient, and consequently, they are the most powerful continuous wave (CW) lasers.