Multicomponent 'dark' cnoidal waves: stability and soliton asymptotes

The problem of steady-state propagation of several mutually incoherent optical waves — components of 'dark' multicomponent solitons and cnoidal waves — through a photorefractive crystal with a drift nonlinearity of the defocusing type is considered and solved. Analytical expressions are obtained for the distributions of the optical field between the components of the resulting solutions, containing up to three self-consistent components inclusive. It is shown that these solutions are stable and that their spatial structure is retained in mutual collisions and after stochastic perturbations of the intensity distributions.