Optimization and characterization of phase-controlled all-optical switching with fiber solitons

Using a variational approach based on the Lagrangian formulation, consisting of an adiabatic perturbation of two coupled fiber solitonlike pulses, we present an optimization procedure for phase-controlled all-optical switching. Large phase intervals for both the parallel- and cross-state of the nonlinear coupler are determined. By means of a unified theoretical framework, which takes into account the effect of cross-phase modulation (XPM), both twin-core fiber couplers and birefringent optical fibers are considered. The influence of several errors in the weaker control pulse-such as time delay and pulsewidth fluctuations-on the transmission characteristics of the nonlinear coupler is also investigated.