title: The power density of a surgical laser beam: its meaning and measurement.
abstract: This paper discusses the fundamental concepts of matter, energy, power, and power density, with specific emphasis on the power density of a laser. It points out that a laser beam does not have a single, unique value of diameter within which all of its radiation is confined. Therefore, a computation of power density requires both a value of diameter, and the value of the fraction of total power which is transmitted within that diameter. Some possible means of measuring diameter, power, and power density are presented.
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D053685:Laser Therapy