title: Inhibition and enhancement of the spontaneous emission of quantum dots in micropillar cavities with radial-distributed Bragg reflectors.
abstract: We present a micropillar cavity where nondesired radial emission is inhibited. The photonic confinement in such a structure is improved by implementation of an additional concentric radial-distributed Bragg reflector. Such a reflector increases the reflectivity in all directions perpendicular to the micropillar axis from a typical value of 15-31% to above 98%. An inhibition of the spontaneous emission of off-resonant excitonic states of quantum dots embedded in the microcavity is revealed by time-resolved experiments. It proves a decreased density of photonic states related to unwanted radial leakage of photons out of the micropillar. For on-resonance conditions, we find that the dot emission rate is increased, evidencing the Purcell enhancement of spontaneous emission. The proposed design can increase the efficiency of single-photon sources and bring to micropillar cavities the functionalities based on lengthened decay times.
authors.affiliation: Institute of Experimental Physics, Faculty of Physics, University of Warsaw , Hoża 69, 00-681 Warsaw, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Jakubczyk
authors.forename: Helena
authors.initials: H
authors.lastname: Franke
authors.forename: Tomasz
authors.initials: T
authors.lastname: Smoleński
authors.forename: Maciej
authors.initials: M
authors.lastname: Sciesiek
authors.forename: Wojciech
authors.initials: W
authors.lastname: Pacuski
authors.forename: Andrzej
authors.initials: A
authors.lastname: Golnik
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Schmidt-Grund
authors.forename: Marius
authors.initials: M
authors.lastname: Grundmann
authors.forename: Carsten
authors.initials: C
authors.lastname: Kruse
authors.forename: Detlef
authors.initials: D
authors.lastname: Hommel
authors.forename: Piotr
authors.initials: P
authors.lastname: Kossacki
keywords: Purcell effect; leaky mode; micropillar cavity; quantum dot; radial-distributed Bragg reflector; spontaneous emission inhibition