Physical principles of LASER

Abstract

Lasers have become an indispensible tool in many branches of medicine due to their ability to produce a narrow beam of light with a specific wavelength, capable of producing tissue damage in a controlled fashion. Those with wavelengths in the infrared, visible or ultraviolet regions are most commonly used for commercial applications. This article outlines: the physical principles of laser; the properties of a laser light beam and the components required to produce it; the mechanisms of tissue damage dependent on the optical properties of tissues and the laser-tissue interaction; and some of the common medical uses of laser therapy. Hazards associated with laser use are discussed as are some of the safety precautions employed to ensure that risk to patients and staff is minimized.