Switching of discrete optical solitons in engineered waveguide arrays

An effective method for controlling nonlinear switching of discrete solitons in arrays of weakly coupled optical waveguides was discussed. The key ideas of the array engineering by means of a steplike variation of the waveguide coupling was demonstrated which was based on the effective discrete nonlinear equations describing light propagation in the waveguide arrays in the tight-binding approximation. The discrete model was used to estimate the Peierls-Nabarro (PN) potential experienced by a strongly localized nonlinear mode that was kicked initially in a cubic nonlinear waveguide array. The result suggests a possible control mechanism for the switching of strongly localized excitations by means of a steplike variation of the waveguide coupling.