High-Q whispering gallery modes in wet etched silica microdisk resonators containing silicon nanocrystals

We demonstrate coupling of room temperature photoluminescence (PL) emission from silicon nanocrystals (nc-Si) embedded in silicon-rich silicon oxide (SRSO) to whispering gallery modes (WGMs) of 10 mu m radius microdisk resonators. The resonators were fabricated by wet chemical etching of circular patterns defined by electron beam lithography and display very smooth edges. We observe nearly degenerate counter-propagating WGMs from the microdisks and measure quality factors of Q > 3500 for the fundamental mode at 850 nm - limited by the absorption loss from the nanocrystals.