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Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. |
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A branch of optics that describes the theory and practice of lasers. |
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A laser can function either as an amplifier or as a light source. As an amplifier, the amplified signal is usually very similar to the input in terms of wavelength, phase, polarisation and direction. As a source, lasers are able to produce a very "pure" light in that the output can have a close approximation to a single wavelength, phase (ie [coherent light]?), polarisation, and direction. These properties have many uses in science and technology. (Please list some here as links.) Alternative light sources with all these properties are typically weak and cumbersome. The basic physics of lasers centres around the idea of population inversion, also called "negative absolute temperature" in some accounts. A great deal of Quantum Mechanics and thermodynamics theory can be applied to laser action, though in fact most of the more useful laser types were discovered by accident or trial and error. Population inversion is also the concept behind the maser, which is similar in principle to a laser but works with microwaves?. Masers were invented in the late 1950s, a few years before lasers. Even earlier was a similar device working at radio frequencies. These were first developed in the 1930s, and further developed in the early 1950s. They don't seem to have a name of their own, possibly because they don't have any obvious practical uses. (Ordinary electronic radio amplifiers and oscillators perform better for less effort.) Some of the basic theory of lasers was in fact developed to explain these earlier devices. (Please list here some typical laser types, either as hotlinks, or as a description and short discussion of theory and use.) (Also, this page is more about Lasers than Laser science, mostly because i'm not really sure what Laser science is. If you know, please add some relevant material.) |
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Laser science is principally concered with [quantum electronics]?, the design of optical resonators, and associated fields such as nonlinear optics. |
Laser science is principally concered with [quantum electronics]?, the design of optical resonators, and associated fields such as nonlinear optics.
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