The laser mechanism often uses visible light, which is a portion of the electromagnetic spectrum made up of the radiation groups called radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.
The electromagnetic radiation is emitted as a narrow, spatially coherent (of the same frequency, phase, and polarization), low-divergence beam, which is called laser light.
The first laser was created on May 16, 1960, just about fifty years ago, by U.S. physicist Theodore Harold 'Ted' Maiman (1927'”2007), who was working at the Hughes Research Laboratories.
Others before him laid out the theory of lasers, including Albert Einstein in 1917 when he described the theoretic foundation for the laser in his paper Zur Quantentheorie der Strahlung (On the Quantum Theory of Radiation).
Now that the laser is fifty years old, Scientific American has come out with a paper that describes the events that led up to its invention.
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