Microcavities combining a semiconductor with a fused-silica microsphere

We report studies of a novel microcavity system that combines a semiconduct or quantum well with a fused-silica microsphere. We show that excitonic pho toluminescence from the quantum well couples efficiently into whispering-ga llery modes. Using a resonant light-scattering technique, we demonstrate th at the Q factor of the combined system exceeds 10(5). Our studies also poin t to the necessity of using semiconductor nanostructures with a capping lay er no more than a few nanometers thick. (C) 1999 Optical Society of America .