Optically pumped ultraviolet microdisk laser on a silicon substrate

Abstract
We have fabricated ultraviolet microdisk lasers on silicon substrates. A thin layer of zinc oxide is grown on top of the silica microdisks and serves as the gain medium. Under optical pumping, lasing occurs in the whispering gallery modes of the hybrid microdisks at room temperature. Above the lasing threshold, a drastic increase of emission intensity is accompanied by a decrease of spectral width of the lasing modes.