Interaction between optical spatial solitons in nonlocal Kerr media

In this paper, it is discussed that a pair of optical beams co-propagates in nonlocal Kerr media, which is governed by the nonlocal nonlinear Schrodinger equation (NNLSE). A new approximate linear model to the NNLSE is presented for the strong nonlocal Kerr media with arbitrary response functions. An analytical solution in Gaussian form to the model is obtained. It is shown that the phase of each of the two beams is depended on the total input power. As a concrete example, the interaction of two beams with the intensity of one of the beams much stronger than that of the other is discussed. It is found that the phase shift of the weaker (probe) beam is very large within rather short propagating distance in the case of soliton, which can be controlled by modulating the input power of the stronger (pump) beam.