We examine crossing waveguides with three channels consisting of nonlinear material by means of FD-BPM (Finite Difference Beam Propagation Method). Specifically, we investigate how the insertion of a multimode waveguide into the crossing section of both 13 and 23 structures influences the switching characteristics of output power. We then confirm that these structures can be favorably applied to a wide variety of all-optical devices for integrated optics such as intensity-dependent optical switches, optical power distributors and so on.

Optical logic gates for OR, AND, NOT, and NOR operations in waveguides consisting of nonlinear material are numerically investigated by means of FD-BPM (Finite Difference Beam Propagation Method). The proposed devices are designed utilizing the self-routing characteristics of nonlinear X-crossing structures when they are operated with one input beam or two. The numerical simulations show that the proposed structures can favorably be applied to optical data processing and computing as fundamental logic gates.