الفهرس 
introduction and aim of the work
The Physical principles of lasersOnly 14 pages are availabe for public view
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Abstract
Laser is an acronym for light amplified by stimulated emission of radiation (Dover, 1990). Laser light has unique properties that enable transmission of high amounts of energy to a narrowly defined site. Biological effects may be thermal, chemical or mechanical. Medical procedures involve mainly thermal tissue destruction by coagulation (>60c) or oblation (> 300c). The effect is goverend by tissue optical and thermal properties and laser variables (Hillegersberg, 1997). The basic principles of the laser can be traced back to Albert Einstein who in 1917 postulated the process of stimulated emission of radiation (Einstein, 1917). Gordon et al. (1954) built the first MASER (an acronym standing for microwave amplification by stimulated emission of radiation). Schawlow and Townes (1958) proposed the idea of building an ”optical maser” which today is known as the laser (replacing the word microwave in the acronym with the word light).