Semiconductor lasers are complex structures with the potential to access huge gain bandwidth in many practical applications. The optical response of the active layer can change drastically depending on the dynamic operating regime of a device. Complex gain lineshapes impose severe constraints on the numerical dispersion of the underlying optical model.

Standard finite-difference discretization introduces numerical dispersion that restricts the dynamics to a small fraction of the physically accessible spectrum. We have developed a new scheme that is based on an optical propagator model realized as a digital filter. Unlike ordinary filters that require excessive storage of time histories, our optical propagator “filters” along the spatial propagation direction of the optical field.

The propagator is extremely efficient and can be parallelized in a transparent fashion. This basic module enables us to build truly interactive optical systems simulators.