Friday, October 25, 2019
Laser Surgery :: Health Medicine Medical Essays
Laser surgery Lasers (The word laser is an acronym for light amplification by stimulated emission of radiation.) lasers were first introduced in 1960, The first successfully optical laser constructed by Maiman (1960), was a ruby crystal surrounded by a helicoilal flash tube enclosed within a polished aluminum cylindrical cavity cooled by forced air. The ruby cylinder forms a Fabry-Perot cavity by optically polishing the ends to be parallel to within a third of a wavelength of light. Each end was coated with evaporated silver; one end was made less reflective to allow some radiation to escape as a beam was produced. Initially the laser was named the invention looking for a job. Photo-pumped by a fast discharge flash-lamp, the first ruby lasers operated in pulsed mode for reasons of heat dissipation and the need for high pumping powers. Nelson and Boyle (1962) constructed a continuous lasing ruby by replacing the flash lamp with an arc lamp.(1) Today lasers are much like those of the early ones and they are widely used in many fields, their uses are wide spread, From fusion physics to the DVD player these are common places where lasers are used. Medicine and surgery are no exceptions from skin resurfacing to eye surgery to correct vision. With the development of lasers Physicians have been able to provide treatment for a large number of medical disorders. Medical lasers have made it possible to treat conditions, which were previously untreatable or difficult to treat. To make the most of the laser technology physicians must maintain a up to date understanding of laser systems and conditions for which each can be applied .To achieve these goals the basic terminology and fundamentals of laser-tissue interaction is needed. Before we can learn about lasers we need to know a little about light, because that is essentially what a laser is made of. First the speed of light is 3.00*10to the 8th meter per second .The American physicist Albert Michelson found a ratio 1.33 for the speed of light c in a vacuum to the lights speed v in water. This value is equal to the index of refraction n thus n=c/v gives us a way to predict the speed of light in any material once we know its index refraction.(2) Lasers produce a intense beam of bright light that travels in one direction. And a laser has the unique ability to produce one specific color or wave length of light which can be varied in its intensity and pulse.
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