Abstract
A new design of an optimized optical system for the reduction of a laser beam size at a certain wavelength is presented. The technique of this design is based upon replacing the elements of a four-lenses optical system, which is designed for this purpose, by one element made of an axial gradient index material. The optical performance of this new design, which has a power as that of its counterpart, is tested by the evaluation of many merit functions. The graphical comparisons between the corresponding values of both systems merit functions show that the new design has a less amount of geometrical aberrations relative to that of its counterpart.