Nonlinear finite-element semivectorial propagation method for three-dimensional optical waveguides

A nonlinear semivectorial beam propagation method based on the finite element method is presented. It applies to three-dimensional optical waveguides and accounts for polarization effects. To show the usefulness of this approach numerical results regarding both E/sup x/ (quasi-TE) and E/sup y/ (quasi-TM) waves are presented for directional couplers with nonlinear cores. The limits of scalar formulations are highlighted especially when working near and above the coupler threshold power.