SOLITON-BASED OPTICAL SWITCHING IN WAVE-GUIDE ARRAYS

We analyze the propagation of discrete solitons in a periodic system o f weakly coupled nonlinear optical waveguides, i.e., a waveguide array . Soliton reflection, transmission, and trapping, as well as coherent and incoherent interaction with a linear guided wave [which can exist owing to defect (inhomogeneous) coupling between two neighboring waveg uides], are demonstrated numerically and investigated analytically wit h a collective-coordinate approach. Some potential schemes of controll able and steerable soliton-based optical switching in nonlinear wavegu ide arrays are discussed. For the first scheme it is suggested that un stable soliton modes be used to achieve easily steerable propagation o f discrete bright and dark solitons. This is to avoid mode trapping by the effective Peierls-Nabarro potential, which always appears because of the system discreteness. The other scheme is based on soliton cont rol with the help of a linear guided wave that can be excited in an in homogeneous array. (C) 1996 Optical Society of America