An acronym that stands for Light Amplification by Stimulated
Emission of Radiation. Lasers emit monochromatic light (a single
color or wavelength), coherent (in phase), and collimated. A
measure of instantaneous power output from the laser; typically
measured in Watts. Length between two identical points on
subsequent electromagnetic waves. The wavelength of a laser
determines it’s color and absorption properties. Power per unit
area; measured at a treatment surface. Lasers are divided into
safety classifications in the US by the American National
Standard Identification (ANSI), and globally by the
International Electrotechnical Commission (IEC). The
classifications below from the revised system (2002) apply to
non-magnified laser devices.