Wave front reversal during nonstationary stimulated Mandel'shtam-Brillouin scattering of focused beams

Consideration is given to the conditions for the existence and observation of wave front reversal in focused light beams due to nonstationary stimulated Mandel'shtam-Brillouin scattering. Experimental observations were carried out for light beams having small scale spatial inhomogeneities at a wavelength of 1.05 microns. The precision of the wave front reversal is determined, and the reflection coefficients of the Mandel'shtam-Brillouin scattering mirrors are measured with respect to quasi-homogeneous light beams under saturation conditions. The relative duration of the light pulses was t sub i/T2 = 0.15-1 (where T2 is the hypersound relaxation time). It is shown that the maximum duration of the pulses, which were reflected by a stimulated Mandel'shtam-Brillouin mirror, was limited by competing nonlinear breakdown and self-focusing processes. The accuracy of a correction for wave front reversal is also determined.