Helmholtz bright and black soliton splitting at nonlinear interfaces

Soliton breakup occurring at the planar boundary separating two Kerr focusing and defocusing media is analyzed within the framework of the Helmholtz theory where the full angular content of the problem is preserved. We show that the number of solitons resulting from bright soliton breakup depends on the soliton angle of incidence, contrary to the predictions of previous paraxial analyses. The generation of multiple gray solitons resulting from the interaction of a dark soliton at Kerr defocusing interfaces is studied and the main properties of the output dark soliton pattern are revealed.