Emission of aberration-free radiation from lasers with active elements made of neodymium glass plates

An experimental investigation was made of the optical quality of active elements made of GLS-22 neodymium glass plates with reflection from polished side surfaces, as used in an UMI-35 laser system. It was found that the active element was optically equivalent to a cylindrical lens. A continuously acting phase corrector compensated wavefront distortions in the active element and ensured that the divergence of the output radiation at the exit aperture was close to the diffraction limit.