A full three-dimensional microscopic simulation for vertical-cavity surface-emitting lasers

Abstract

A three-dimensional simulation tool for verticalcavity surface-emitting lasers is presented. The microscopic electronic equations are solved in all spatial directions, and a separation approach is used for the electromagnetic equations in frequency domain. Selected examples requiring a threedimensional treatment are discussed, e.g. spatial hole burning for higher-order modal operation.Index Terms-VCSEL, simulation, semiconductor, microscopic I. I NTRODUCTION HE mainstream of commercial vertical-cavity surfaceemitting lasers are designed having a rotationally symmetric optical cavity. This ensures a stable circular optical output beam with optimum coupling to fibers or lenses. The microscopic simulation of this class of devices can exploit this fact by using a two-dimensional geometric model with the equations being formulated in cylindrical coordinates [1]. Recently, there have been novel VCSEL designs which include lateral photonic crystal waveguides [2] or inhomogeneous current injection schemes in order to improve the specifications such as single mode stability. In order to apply predictive technology computer-aided design (TCAD) methods, a full three-dimensional geometric model is required. In this presentation, a three-dimensional microscopic multi-mode VCSEL simulator will be presented. It is based on the multidimensional laser simulator DESSIS [3], and as further development to previous codes [4], includes ballistic scattering equations for the quantum-wells, and multi-mode capabilities.