Combined analytical-finite difference time-domain full wave simulation of mode-locked vertical-extended-cavity semiconductor lasers

Abstract

A time-domain approach based on the finite difference time-domain (FDTD) method is described for vertical-extended-cavity surface-emitting lasers (VECSELs). To permit the simulation of realistic devices with large extended cavities a combined analytical-FDTD model is developed. This approach uses plane wave propagation in the linear extended cavity to couple the active mirror and the semiconductor saturable absorber mirror (SESAM) in which the standard FDTD method is applied. This allows for a significant computational time reduction. The material response in the active quantum wells (QWs) and the absorber is incorporated by an infinite impulse response digital filter. The model is validated by the simulation of a passively mode-locked VECSEL with a multiple QW active region and a single QW SESAM.