Time-resolved probing of the Purcell effect for InAs quantum boxes in GaAs microdisks

We studied, by time-resolved microphotoluminescence (PL), the spontaneous emission dynamics of InAs/GaAs quantum boxes coupled to high Purcell factor (up to 155) whispering gallery modes of microdisks under nonresonant excitation. A global shortening of the PL decay by a factor of up to 12 was observed for the collection of quantum boxes on resonance with the modes. This behavior is well understood when the random distribution of the quantum boxes and the finite relaxation rate of the carriers are taken into account.