Investigation of systems for obtaining short high-power pulses by wavefront reversal of the radiation in a stimulated Brillouin scattering mirror

An investigation was made of optical systems performing wavefront reversal of the radiation in a stimulated Brillouin scattering (STBS) mirror and used to generate short ($\sim10^{-9}$ sec) high-power pulses in neodymium-glass amplifiers. For a single-channel system the most suitable arrangement in practice was one in which reflection with wavefront reversal by an STBS mirror took place under steady-state STBS conditions, while a short pulse of the required duration was chopped out of the reflected radiation by a special switch. A method was found for eliminating depolarization of the radiation and inhomogeneities in the transverse distribution of the gain in the neodymium rods and this made it possible to achieve wavefront reversal of the radiation in a high-power laser system with a diffraction-limited accuracy ($E\approx50$ J, $\tau\approx2$ ns, $\theta\approx2\cdot10^{-5}$ rad).