Numerical analysis of all-optical switching based on a 2-D nonlinear photonic crystal directional coupler

A photonic crystal (PhC) all-optical switch based on a nonlinear directional coupler is presented and discussed. The coupling strength of the structure may be tuned by a high optical power control signal that propagates along the coupling region. Thus, the power ratio between the output ports of the device can be tuned and, hence, switching is accomplished. The study of the present structure is performed with a numerical tool based on the finite-element method. This tool allows to calculate the nonlinear band diagram of a two-dimensional PhC. The implementation and characteristics of this method are thoroughly addressed.