Polarization ray tracing in thermally loaded solid-state laser crystals

A new ray tracing method for the propagation of electrical fields in inhomogeneous and weakly anisotropic media is presented. With this method, we can efficiently simulate the propagation of laser beams in solid-state laser amplifiers, which suffer from high thermal loads. As a result of this method, we can find optical compensation setups that significantly reduce the depolarization losses in high-power solid-state amplifiers. To the best of our knowledge, we theoretically demonstrate for the first time that [100]-cut YAG crystals reduce the depolarization by more than a magnitude in comparison to [111]-cut crystals while achieving an overall better beam quality at the same time. (C) 2020 Optical Society of America