BEAM QUALITY DEGRADATION OF POLARIZED, CIRCULARLY SYMMETRICAL BEAMS CAUSED BY A BIREFRINGENT ND-YAC ROD

The effects that a birefringent rod produces in the beam-quality facto r of a polarized, circularly symmetric laser beam are studied. Analyti cal expressions for the beam parameters at the output plane of a Nd:YA G rod amplifier have been derived. Numerical calculations are carried out for Supergaussian and Laguerre-Gaussian beams. It has been shown t hat in these cases the quality degradation factor depends only upon tw o parameters, i.e. the normalized heating power and the beam shape. Th e results are very useful for designing high-power amplifier systems.