Abstract

Vertical cavity surface emitting lasers (VCSEL's) are very promising devices for parallel optical data links. Their main qualities are wafer scale testability, inherent single longitudinal mode operation, low threshold current, low beam divergence and their easy integration in two-dimensional arrays. Due to their intrinsic symmetry and quite large emission area problems arise however concerning the transverse mode stability. Unless specific measures are taken to prevent this higher order transverse modes start lasing already slightly above threshold thereby deteriorating the beam properties (e.g. divergence) and increasing the noise. It is obvious that this behaviour is unwanted. One way of solving this problem is by introducing mode selective scattering or loss in the cavity [1,2,3,4], It is therefore important to be able to model the threshold gain of the different transverse modes in such cavities. In this paper we present an accurate vectorial model capable of predicting threshold gain and illustrate is with a few examples.

© 1996 Optical Society of America