Short optical pulse switching in three-core nonlinear piper couplers

The propagation and switching of short optical pulses in a three-core nonli near fiber coupler have been investigated with a variation method within th e framework of the Lagrangian density formulation. The analytical solutions were directly obtained from the coupled nonlinear Schrodinger equations. I t is shown that the soliton switching behavior predicted by the present ana lytical method agrees well with the results from numerical analysis. In add ition,the coupling length and the switching threshold of solitons in a nonl inear coupler were obtained.