The ray packet equivalent of a Gaussian light beam.

A packet of light rays is defined that is equivalent to a Gaussian beam of light. The transformation of the Gaussian beam as it passes through any combination of perfect lenses and flat dielectric interfaces can be found by applying geometric optics to the equivalent ray packet.. The envelope of the ray packet gives the Gaussian beam spot size and the curves perpendicular to the average ray slope give the Gaussian beam phase fronts.