Finite element simulation of optical modes in VCSELs

An important ingredient of VCSEL device simulation is the solution of the optical model. Challenges are the multiscale structure of realistic devices with thin layers in the Bragg mirror and active zone on the one hand and large total resonator volumes on the other hand. In order to compute the resonating modes and frequencies, Maxwell eigenvalue problems have to be solved on these geometries. Thereby, also layered infinite exterior domains have to be respected. In commercial simulation packages the optical problem is often restricted to geometries with cylindrical symmetry or even only simplified 1D material stacks are considered. However, with increasing complexity of devices and novel design ideas like inclusion of photonic crystal structures, full 3D modeling of VCSELs becomes very important. In our contribution we present the finite element method for computation of the optical resonance modes and corresponding far fields in VCSELs. We investigate realistic 3D devices and quantify numerical effort and accuracy.