Abstract
Heat flow finite element analysis is applied to basic device concepts, including planar structures with InGaAsP/InP or AlAs/GaAs substrate side mirrors (mounted top-up or top-down) and etched-well lasers with Si/SiO2 dielectric mirrors. In several cases, the calculated thermal resistance values are higher than with short-wavelength devices, but wafer-fused structures on GaAs substrate show clear thermal advantages.