High-Q whispering gallery modes from a combined system of GaAs quantum well and fused silica microsphere

Summary form only given. We have developed a microcavity system that combines a semiconductor quantum well (QW) with a fused silica microsphere by placing the QW in the evanescent field of whispering gallery modes (WGMs) of the microsphere. This combined system takes advantage of the extremely high Q-factor and very small mode volume of the WGMs and allows separate engineering of electronic and photonic confinement, thus opening up a new approach for cavity QED study of semiconductors. We show that photoluminescence (PL) from the QW can couple efficiently into the WGMs of the microsphere and the Q-factor of the combined system exceeds 4/spl times/10/sup 5/ even when the sphere is in contact with the QW sample.