Multidimensional noise model and simulation of VCSEL devices

A novel spatially distributed noise model is used in a device simulator in order to describe relative intensity noise and frequency noise for semiconductor lasers. For charge carrier transport, continuity and Poisson equations are used and self-heating is considered by a thermodynamic equation. Spontaneous and stimulated recombination are calculated in the framework of the semiconductor Bloch equations using the second Born approximation to include many-body effects. The optical field is expanded into modes. The temporal behavior is described by a photon rate and a photon phase equation for each mode. Noise is taken into account by spatially distributed Langevin forces. The correlation functions are described directly in the frequency domain assuming small signal noise sources. All relevant equations are solved in a fully self-consistent fashion. Comparison of static characteristics and dynamic characteristics, such as relative intensity noise, with measurements show excellent agreement for a vertical-cavity surface-emitting laser (VCSEL).