A Standing-Wave Model Based on Threshold Hot-Cavity Modes for Simulation of Gain-Coupled DFB Lasers

A time-domain standing-wave model is proposed and developed to analyze the gain-coupled DFB laser. In this model, the optical field is decomposed into a set of eigenmodes, which are longitudinal cavity modes obtained when the laser is biased near threshold, i.e., threshold “hot-”cavity modes. As such, the spatial and temporal dependence of the optical field is separated with optical modes describing the spatial dependence and their amplitudes governing the temporal evolution of the field. Important effects such as the variation of the coupling coefficient with the injection level and the spatial hole burning can all be taken into account.