Dispersive radiation and nonlinear twin-core fibers

Abstract

The switching of optical solitons in a nonlinear fiber coupler is investigated by an approximate variational method that includes the effect of dispersive radiation. The solutions of the variational equations are in good agreement with full numerical solutions of the coupled nonlinear Schrodinger equations that govern the fiber coupler. In particular, it is found that to obtain an accurate description of the switching process and of the evolution of the solitary waves in each core of the fiber coupler one must include the effect of the dispersive radiation shed as the solitary waves evolve. As a consequence, the present variational method gives much improved results compared with other variational methods that do not include dispersive radiation.