Modal competition in implant-apertured index-guided vertical-cavity surface-emitting lasers

We present a detailed theoretical study on the optical and L–I characteristics of implant-apertured index-guided vertical-cavity surface-emitting lasers. Our theory is based on a beam propagation method combined with thermal, gain, and rate-equation models. Spatial hole burning and modal competition are taken into account. Our results are in excellent agreement with the experimental data and show the effect of the current aperture size (determined by the ion implant) on the modal performance of these devices. In particular, the current-aperture size can be fixed independently from the index-guide size to obtain minimum threshold, single-mode operation.