Intensity distribution properties of a Gaussian laser beam focus.

A generalized method for determining the properties of a Gaussian laser beam focus including waist radius, position, and intensity distribution is presented. Of significance to in situ laser diagnostic methods is a unique analysis of illuminated area as a function of intensity in a plane of the laser beam. The results apply for nontruncating diffraction-limited optical systems and are important in determination of the optical sampling volume of laser instruments for particulate and gaseous species analysis.