Perturbation of solitons due to power law nonlinearity

The generalization of solitons to a non-Kerr law media has been studied in this paper along with its perturbation. In particular, the higher nonlinear Schrödingerʹs equation (NLSE) due to power law nonlinearity is considered. The method of multiple-scales is used to study this equation in presence of a perturbation term. We show that, by newly introducing a proper definition of the phase of the soliton, for the first time, one can obtain the corrections to the pulse where the usual soliton perturbation approach fails.