Analysis of ultra short pulse propagation in optical directional coupler structures

We employ an efficient time-domain beam propagation technique to study the effect of the propagation of ultra short pulse duration on the behavior of directional coupler operation. The technique used is based on higher order non-paraxial formulation that takes into account the spatiotemporal coupling effect which is crucial for the proper propagation of ultra short optical pulses. In this work the characterization of pulse spread and broad frequency content interactions of short pulse propagation have been analyzed. We validate in this rigorous analysis that the intermodal dispersion of the structure changes the behavior of the well known operation and breaks up the pulse during propagation which gives rise to distortion.