الفهرس 
Laser FundamentalsOnly 14 pages are availabe for public view
 |  | from | 163 |  |  |
| | | from | 163 | | |
Abstract
The word laser is an acronym for light amplification by stimulated emission of radiation. The history of laser devices is recent, although the fundamenta principles of lasers are based on the develop¬ment of quantum theory in 1900s. The first laser demonst¬rated was the visible ruby laser by Maiman in 1959. All lasers have four basic components: the active medium, the power supply, the o ot i ca l cavity and the deli¬very system. Laser light itself has little effect on tissue that either fully reflects it or is completely transparent to it; instead,’ the extent of laser’s effects on tissue are determined by its wavelength. Safety is a vital factor common to all laser procedures. Precautions or the level of hazard may differ, but the approach to safety will not change. Over the past 10 years, laser has changed the clinici¬an’s approach to both benign aruL malignant tracheobronchial di seas e. Les ions, such as non r e s e ct able, recurrent or persistent malignancy that were previously regarded as un¬treated by more conventional modalities have been managed successfully with laser through an endoscopic approach.