ENHANCEMENT OF SPONTANEOUS EMISSION RATES BY 3-DIMENSIONAL PHOTON CONFINEMENT IN BRAGG MICROCAVITIES

Three-dimensionally confined Bragg microcavities exhibiting several fu lly quantized photon modes have been investigated by time-resolved pho toluminescence spectroscopy. A strong decrease of the exciton lifetime with decreasing lateral dimension is observed and shown to be mainly due to coupling of the long-lived excitons with short-lived photon mod es. We observe similar decay times of all photon modes for a fixed str ucture size which amount to approximately half of the corresponding ex citon lifetimes. This behavior is explained by incoherent Auger-type s cattering processes populating the photon modes on the low-energy side of the exciton line.