Interactions of coherent or incoherent spatial soliton pairs in the vicinity of a non-linear interface

Soliton switching due to soliton-soliton interaction was suggested previously. More efficient "digital" switching can be achieved when the soliton interaction is taking place in the vicinity of a non-linear interface. When a single spatial soliton is incident at an oblique angle on an interface separating two positive Kerr like media, it is transmitted, reflected or trapped by the interface depending on its intensity. We study the interactions of two solitons near a non-linear interface both by a numerical solution as well as by deriving a new potential for the combined two particle and interface interactions. The results predict efficient soliton-controlled soliton-switching. First we examined numerically the interaction of two coherent/incoherent spatial solitons with a non-linear interface. The initial conditions - the separation between the solitons and their angle of incidence were set to yield interactions only close to the interface. The interaction of non-equal amplitude spatial solitons - which are typical to the switching scenario - with an interface was studied. The presence of a second (control) soliton near the interface was found to have a remarkable effect on the first soliton.