Brillouin reversal of optical fields with a time-dependent speckle structure

An analysis is made of stimulated backscattering in the case when the pump (laser) radiation has a continuous frequency spectrum and a time-dependent (nonfactorizable) speckle structure. The gain increments μ (p) and the corresponding specklon solution for a Stokes wave are found in the case of an arbitrary ratio of the widths of the pump line Δω_l, and of the stimulated scattering line Γ. These solutions correspond to partial wavefront reversal, i.e., to reversal of the spectral band of the pump radiation within an interval of width of the order of Γ/2 around a certain frequency p. A comparison of the specklon gain increments with the increments for uncorrelated waves makes it possible to determine the conditions for wavefront reversal.