Room-temperature optically-pumped GaSb quantum well based VCSEL monolithically grown on Si (100) substrate

Monolithic vertical cavity surface emitting lasers (VCSELs) on Si are demonstrated. The GaSb multi-quantum well active region embedded in an Al(Ga)Sb half-wave cavity spacer layer enables lasing under room-temperature optically-pumped conditions. The 13% lattice mismatch is accommodated by a spontaneously formed 2-D array of 90 misfit dislocations at the AlSb=Si interface. This growth mode produces very low defect density ( 8 10=cm) and relaxed materials growth (98%) without the use of a buffer layer. Presented are VCSEL lasing spectra, light-in against light-out curves along with defect density measurements performed by microscopy and etch-pit density. A threshold excitation density of Ith1⁄4 0.1 mJ=cm and a multimode lasing spectrum peaked at 1.62 mm, results from a 3 mm pump-spot size.