Spatial vector soliton in nonlocal nonlinear media with exponential-decay response

The propagation of two orthogonally polarized incoherent optical beams in strong nonlocal nonlinear media with exponential-decay response was investigated by a variational approach, and the analytical result was confirmed by numerical simulation. The evolution equations for the parameters of the two beams were obtained and a spatial vector soliton was found. The effects of coupling coefficient and birefringence on the propagation of the two beams were discussed. A soliton-like wave, which is different from the vector soliton, was discovered. Moreover, the phase shifts of the two beams are different under certain conditions and the propagation distance of generating π phase difference can be figured out. These theoretical result have the potential application to developing the logical devices or optical switching, which based on the principle of phase difference or polarization.