Counterpropagating photorefractive spatial solitons

This study introduces a model for the interaction of counterpropagating spatial solitons using the photorefractive screening nonlinearity. To correctly describe the type of interaction considered, the model takes into account the spatial propagation of the light field as well as the temporal evolution of the screening space charge field. The model equations are evaluated numerically for incident beams with a varying degree of mutual coherence. Depending on the strength of the nonlinearity and the degree of coherence, as well as on the incident geometry, i.e. the lateral offset and the angle between both beams, a broad range of behavior is reported.