The laser was invented in 1958 with the publication of the scientific paper, Infrared and Optical Masers, by Arthur L. Schawlow, then a Bell Labs researcher. The word laser stands for "Light Amplification by Simulated Emission of Radiation." A laser is a concentrated beam of light, created when a electric current passes through a special material.
The name and the color of the laser depend on the type of special material that is used:
Generating coherent monochromatic light requires the right atoms with the right internal storage mechanisms to create an environment in which the atoms give up their light at the right time, in the same direction.
Laser basics.
