Abstract

Gaussian optical beams, as generated by the most common laser resonators do not provide always the most efficient means of extracting energy or power from a given gain medium. This fact, which was recognized at early stages of the development history of lasers gave rise to alternative concepts of laser resonators like unstable configurations^[1] or the use of variable reflectivity mirrors (VRM).^[2] Both concepts proved successful in improving both the laser efficiency and optical quality of generated beams. The object of this work is to approach the question of efficiency optimization and optical beam shaping in lasers in the most appropriate way under constraints like amplifier gain distributions, overall system size and cavity apertures location. The approach is based on the use of variable transmission elements and/or aspheric mirrors surfaces of the most general profile. Control on the amplitude and phase transverse profile of outcoming laser beams is also advantageous when considering subsequent beam handling like focusing for materials processing, coupling into waveguides and fibers, avoiding of hard edges and so on.

© 1992 IQEC