  An extensive study of the alignment between the pump, the signal and the
polarization dependent gain (PDG) vectors in stimulated Brillouin amplification
in randomly birefringent fibers is realized by numerically integrating the
equations governing the propagation. At the fiber output, the signal tends to
align to the PDG vector for large pump power because of the nonlinear
polarization pulling effect. The PDG vector, for large random birefringence,
aligns to a state that has the same linear component of the pump but opposite
circular component.
