Influence of aberrations on fundamental mode of high power rod solid-state lasers

We investigate the influence of thermally induced higher order aberrations on the fundamental mode of a rod solid-state laser, The perturbations of the laser due to the most common aberrations (spherical aberration and astigmatism) are studied for several sizes of the fundamental mode. Results concerning the additional losses and beam quality degradation induced by these aberrations are also presented and demonstrate that for a large overlapping of the beam size and the laser rod, the spherical aberration amplitude must not exceed 0.5lambda for the cavity to oscillate. The influence of gain saturation also analyzed in the model is shown to be of less importance, (C) 2002 Elsevier Science B.V. All rights reserved.