A lens system for shaping a laser beam profile has been designed, built, and tested. It consists of two plano-aspherical lenses which convert a Gaussian input beam into a uniform irradiance output beam. The optical design is based on solving differential equations expressing conservation of energy and constant optical path length condition as the beam passes through the system. Experimental results for the irradiance profile and wavefront shape of the output beam are presented and discussed. When this beam shaping system is used with light of different wavelengths than the design value, experimental results show that a small change in lens spacing enables the beam shaping optics to operate efficiently. An experimental tolerance analysis of this beam shaping system shows that it is stable with respect to assembly errors of tilt and misalignment of components.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.