Two-dimensional simulation of laser diodes in the steady state

A fully self-consistent steady-state two dimensional model of laser diodes is presented. The model consists of the simultaneous solution of the Poisson and the electron and hole drift-diffusion equations, the wave equation, and the photon rate equation. Excellent agreement with experiment is obtained for both gain-guided and index-guided laser diodes. Specific results are given for channeled-substrate planar (CSP) lasers. It is shown that comparable electron current confinement is provided by both internal strips (p-GaAs barriers) and zinc-diffused planar stripes. The confinement in the first case is due to energy barriers and in the latter case is due to lateral electric fields. For the holes, current spreading is shown to be reduced substantially for the planar stripes because of the use of high-resistivity n-cap layers. It is demonstrated that the thickness of the p-GaAs layers can be smaller than the minority carrier diffusion length since only a very small fraction of the laser light passes through the barriers.>