Optimisation of phase-conjugating mirrors made of nematic liquid crystals in a two-pass laser amplifier

A study was made of a two-pass laser amplifier with a phase-conjugating mirror operating on the basis of forward scattering of intersecting optical beams in a layer of a nematic liquid crystal on the mirror. The reflection coefficient of the mirror was optimised by the selection of the liquid-crystal cell temperature and of the absorption coefficient of the nematic mixture. A study was made of the compensation of the thermal aberrations in the amplifier rod during a return trip of the phase-conjugated scattered beam through the amplifier.