DETECTOR-ENCLOSED VERTICAL-CAVITY SURFACE-EMITTING LASERS

The Letter reports the use of novel monolithic lateral photodetectors surrounding vertical-cavity surface emitting lasers to determine the r adiative transition rate and lasing threshold independent from the axi al emission. The lateral detector photocurrent increases with increasi ng laser drive current, even as the axial emission rolls over and term inates. This clearly establishes that laser output is limited by the d etuning between the Fabry-Perot cavity resonance and the gain bandwith with temperature, rather than the temperature dependence of the gain.