Beam profiling quantifies light sources.(Tutorial)(Brief Article)

Applications ranging from optical telecommunications to bar-code scanning require precise characterization of light beams. Ideally, you could characterize a beam with a single number that defined its width or diameter. Unfortunately, beams--even laser beams--don't have sharp edges, and measurements require a judgment about the portion of a beam that contains "useful" energy.

[GRAPHIC OMITTED]

For the Gaussian power distribution that beams typically exhibit, you can specify the "1/[e.sup.2]" diameter--the points at which beam power density measures 13.5% of m