LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. It is an electrical optical device that creates and emits coherent light radiations. Coherent light radiations are those in which all the waves have same phase and frequency. Resonant effect is the principle on which a laser works. A distinctive laser emits a low divergent, narrow beam of monochromatic light which has a fine wavelength spectrum. Laser light in this respect is in complete contrast with light sources such as the incandescent bulbs that cover a wide area of wavelength spectrum and emits light over a lager area.
A typical laser has a gain medium surrounded by an extremely reflective optical hollow and a mean to provide energy to the gain medium. The working model of a laser was first demonstrated on 16th May 1960 by Theodore Maiman at the Hughes Research Laboratories. Laser has since then been employed for a number of uses and has become a multi billion industry. The most general use of laser technology is in optical storage devices such as DVD and compact disc players. Bar code readers, laser pointers and laser printers also use lasers. Lasers are also used by workers to cut and weld metals. Laser has been used in various fields typically science because of their wavelength and short pulse period.
Laser technology has successfully been employed in health care industry for performing cosmetic applications and delicate surgeries such as the eye surgery. Lasers are also used for military operations such as target identification, range finding and lightning for weapon delivery. Laser has always been considered dangerous and even a low power laser of only a few milliwatts power can cause problems to human eyesight. Laser devices such as DVD player, compact disc players and laser pointers are referred to as eye safe and usually belong to class I, II or III of safety class for laser products.
Invention of laser technology has been a boon for science and has been employed in many fields. The most important use of laser has been in Space program and NASA has employed it in developing spectrometer for mission to Mars.