Phase conjugation of large-aperture laser beams

Phase conjugation of radiation with a divergence of 6 X 10 ^– 6 rad and compensation for the aberrations of an objective were achieved using hypersonic phase conjugate mirrors with a high conjugation parameter, corresponding to the diffraction limit for a ~ 44 cm aperture and indicating a high precision of phase conjugation, amounting to at least 2 X 10 ^– 6 rad. The experiments were carried out using a neodymium laser beam with an energy of at least 0.03 J and a pulse duration of ~ 50 ns.