Integration of Traveling Wave Optical Device Models Into an MNA-Based Circuit Simulator

This article presents a method for integrating traveling wave models (TWMs) into an optical circuit simulator based on modified nodal analysis (MNA) techniques previously developed for electrical circuit simulation. TWMs of optical propagation through waveguides provide flexible distributed descriptions of optical devices from simple waveguides to lasers. The model is, however, by definition an explicit time marching method and does not fit naturally into an MNA formulation. This article will show a method of integrating the TWM into a fully implicit multidomain (electrical/optical) circuit simulator based on MNA techniques. It will first describe the TWM for simple optical propagation and then its extension for optical gratings, amplifiers, and lasers. The integration of the TWM model into the MNA-based engine will then be specified, showing how the model is implemented using nonlinear optical sources. Finally, a set of examples, including waveguides, filters, and electro-optic devices will be used to show the effectiveness of the technique.