Microscopic modeling and simulation of transverse-mode dynamics of vertical-cavity surface-emitting lasers

The dynamics of transverse modes of vertical-cavity surface-emitting lasers were simulated by use of a model that incorporates microscopically computed gain and refractive index with many-body effects. The model equations were solved by finite-difference methods in two-dimensional space and time domains without any a priori assumptions of symmetry of solutions or types and number of modes. Simulation was carried out for devices with and without index guiding at various pumping levels. We show that index-guided vertical-cavity surface-emitting lasers involve more transverse modes than purely gain-guided devices at the same pumping level. Both time-resolved and time-averaged near-field patterns over several time scales are investigated. Complicated spatial and temporal dynamic behaviors occur at higher pumping levels that include azimuthal rotating waves and intensity oscillations owing to dynamic competition between modes of the same order and those of different orders.