Optimal configurations of active regions in nitride VCSELs

A detailed self-consistent threshold simulation of the pulse operation at room temperature (RT) of GaN-AlGaN-AlN vertical-cavity surface-emitting lasers (VCSELs) is developed in a simple mathematical way. Multiple-quantum-well (MQW) VCSELs are proved to be the best suited for an efficient operation of nitride VCSELs. Their optimal number of QWs is proportional to all optical losses within their resonators. Gain-guided QW VCSELs are found to exhibit thresholds comparable to much simpler double-heterostructure (DH) VCSELs, especially for higher optical losses, when DH devices are even becoming the lowest-threshold nitride VCSELs. The single-quantum-well VCSELs occurred to be very sensitive to any increase in optical losses, which practically excludes them from a possibility of manufacturing efficient nitride VCSELs using currently available technology.