Purcell effect on CdSe/ZnSe quantum dots in pillar microcavities

The Purcell effect leads to an enhancement of the spontaneous emission in a given cavity mode for an emitter located in a small volume cavity. This effect is well explained as a consequence of Fermi's golden rule in a particular photonic environment. In this paper we show an enhancement by a factor of up to 3.4 of the spontaneous emission of CdSe/ZnSe quantum dots located in a pillar microcavity. The sample consists of a λ /2-ZnSe cavity sandwiched between SiO2/TiO2 Bragg mirrors and is etched to provide lateral optical confinement. The present study is based on a comparison between time-resolved photoluminescence measurements for dots inserted in a pillar cavity or in a bulk ZnSe layer. The photoluminescence decay shortening is quantitatively interpreted by calculating the theoretical maximum Purcell factor expected for different cavity modes in resonance with quantum dots. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)