All-Optical Logical Gates with Solitonlike Pulses in Mismatched Two-Core Fiber Couplers

In this paper, all-optical logical gates based on mismatched nonlinear two-core fiber couplers are proposed. In these devices, solitonlike logical input pulses are shown to avoid pulse breakup to perform logical operations. The mismatched two-core fiber couplers can be produced through slightly different cores embedded in the same cladding. In this situation, the two cores have different dispersions but practically the same nonlinear coefficients. Due to the different dispersions, the cores have different input critical powers. This enables the cores to be operating in different regimes. They can, independently, be operating in the linear or in the nonlinear regime.