Nonlinear switching of optical solitons in fiber Bragg gratings with non-instantaneous Kerr nonlinearity

Abstract

Introduction:Optical soliton switching in nonlinear uniform fiber Bragg gratings with non-instantaneous Kerr nonlinearity is numerically investigated. Two cases of pulse propagation are considered: propagation through the reflection and transmission regions. Objectives:The purpose is to investigate the influence of a delayed response of the Kerr effect on the switching characteristics of uniform fiber Bragg gratings and compare to the instantaneous nonlinear regime. Methods:A modified set of nonlinear coupled mode equations are numerically resolved on a two-dimensional grid using an implicit four-order Runge–Kutta method. Results:It is found that the reflectivity of the gratings only depend on the relaxation time of the grating medium when the input pulse intensity reaches a certain level. In addition, marked differences in shape of the reflected and transmitted pulses are observed.