Single quantum dot controlled gain modulation in high‐Q micropillar lasers

Abstract

AbstractWe present single quantum dot lasing effects in optically pumped high quality (Q) micropillar cavities. The micropillar cavities are realized by means of high resolution electron beam lithography and plasma etching on planar microcavity structures grown by molecular beam epitaxy. We observe lasing action for micropillars with a diameter as small as 1.0 μm containing on average less than 80 QDs in the active layer. Pronounced single quantum dot (QD) controlled lasing effects are observed by tuning a single QD exciton on resonance with the lasing mode. When lasing action is due to the contribution of an ensemble of QDs, photon autocorrelation studies of the emitted photons reveal a transition from thermal light to coherent light near threshold pump power. In contrast, single QD gain modulation which helps to lower the threshold pump power of a 1.6 μm micropillar by a factor of two, is reflected in non‐classical photon antibunching up to about two times the on‐resonance threshold power. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)