PROJECTS: Efficient and High Power MWIR VECSELs
This project aims at fabricating an optically pumped vertical cavity surface emitting laser (VECSEL) with high output power at 2µm emission wavelength. The laser’s active region includes GaInSb/AlGaSb type I quantum wells. The optical cavity is provided by a high reflectivity AlGaAs/GaAs distributed bragg reflector (DBR) and an external mirror which also serves as the output coupler. The novelty in this project is the combination of a GaSb based active region with a GaAs based DBR, both of which are monolithically grown on a GaAs substrate. The strain due to the lattice mismatch between the GaSb-based active region (lattice constant close to 6.1 Å) and the GaAs-based DBR (lattice constant close to 5.65 Å) is relieved by the formation of an interfacial misfit (IMF) array at the GaSb/GaAs interface.