  Possibility of beam combining and clean-up using Orientational Stimulated
Scattering in a Nematic Liquid Crystal is considered. We numerically study the
dynamics of the process and find that back-conversion process tends to limit
the effective interaction strength. Instability of the steady state of
cross-phase modulation is demonstrated, when both waves have the same
frequency. We show that high conversion efficiency can be achieved, and that
the shape and wave-front of the amplified output signal are robust with respect
to amplitude and phase distortions of the input pump.
