Comprehensive modelling of wave propagation in photonic devices

A simple and powerful modelling method in the time domain is established to resolve travelling waves inside photonic devices. The basic idea is to transform usual space-time coordinates (z, t) into a mixed grid (u, v) in which waves propagate along their characteristic lines, resulting in an inherent numerical stability, as well as easy interpretation of all parametric variables and their derivatives. In this study, the authors will demonstrate, for the first time, how the effect of gain dispersion can be dealt with using an efficient fourth-order algorithm, which attains high precision, high speed as well as very large stepsize. Excellent agreement with existing analytical results is obtained.