8.3 Lasers
The word LASER is an acronym for light amplification by stimulated emission of radiation, which sums up the operation of an important optical and electronic device. The laser is a source of highly directional, monochromatic, coherent light, and as such it has revolutionized some longstanding optical problems and has created some new fields of basic and applied optics. The light from a laser, depending on the type, can be a continuous beam of low or medium power, or it can be a short burst of intense light delivering millions of watts. Light has always been a primary communications link between humans and the environment, but until the invention of the laser, the light sources available for transmitting information and performing experiments ...