Threshold gain temperature dependence of composite resonator vertical-cavity lasers

Vertical-cavity surface-emitting lasers (VCSELs) with two optically coupled but electrically isolated cavities form composite resonator vertical-cavity lasers (CRVCLs). These devices may lase at one of two wavelengths depending on the bias conditions to the two cavities and temperature. A model of the modal gain is presented, which explains the lasing wavelength at threshold based on the spatial and spectral overlap of the microcavity optical modes with the two gain regions.