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Laser is an acronym for light amplification by stimulated emission of radiation. In the last century many types of lasers have been used for many different applications from welding to surgery to military and even many uses in every day life by harnessing the ....

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.... a crest or trough therefore combining to form a wave that has an amplitude equal to the sum of the individual amplitudes of the original waves. Stimulated emission is the process that the laser works on, which was first proposed by Albert Einstein in 1917. When a sufficient number of atoms, either gas solid or liquid, absorb energy so that they are in an excited state of higher energy stimulated emission can occur. Light of a specific wavelength can produce more light with the same phase and direction these light waves will be coherent. Stimulated emission amplifies the coherency of this radiation and gives the radiation a very narrow beam sprea ....