All-optical switching phenomena based on the transmission of coupled-gap solitons in nonlinear periodic dielectric media

We study the propagation of two pulses with orthogonal linear polarizations in a nonlinear periodic dielectric structure with {dollar}chisp{lcub}(3){rcub}{dollar} nonlinearity. Using an envelope-function approach, we derive the coupled nonlinear Schrodinger equations governing the spatio-temporal evolutions of the two orthogonally polarized modes in a nonlinear periodic structure. We then find their solitary-wave solutions referred to as coupled gap solitons. We show that two orthogonally polarized pulses can co-propagate as a coupled gap soliton through a nonlinear periodic structure while each pulse alone will be strongly reflected due to the Bragg reflection. Based on the results, we present an all-optical switching scheme, which has a novel architecture and principle. We also studied the stability of coupled-gap solitons and dragging phenomena in a nonlinear birefringent periodic medium.; Finally, we investigate the switching performance with a corrugated GaAs waveguide as the nonlinear periodic structure and show the potential promise of the proposed device. The technical problems in an actual periodic waveguide are also treated.