A laser (acronym for Light Amplification by Stimulated Emission of Radiation)
produces a monochromatic, coherent and collimated bundle of radiation. The exact
wavelength of a laser beam depends on the nature of the used medium and may vary
from X-ray, ultraviolet, visible light, near- and far infrared to microwaves. In medical
science infrared lasers are used for soft- and hard tissue surgery and for treatment of
fungus and acne scars. Infrared lasers are also applied for hair removal.