Influence of the nonlinear anisotropy of absorption in a passive Cr4+:YAG switch on the energy and polarisation characteristics of a neodymium laser

An experimental investigation was made of the polarisation characteristics of a solid-state neodymium laser with a passive Cr⁴⁺:YAG switch. The energy and the state of polarisation of laser radiation were affected radically by the orientation and position of the Cr⁴⁺:YAG switch in the cavity, and also by the nature of an intracavity polariser. The polarisation characteristics of the laser radiation were determined by a self-induced nonlinear-absorption anisotropy and a self-induced change in the state of polarisation of the laser radiation during growth of a giant pulse when saturation of the absorption was 'switched on' in the Cr⁴⁺:YAG crystal.