Properties and prospects of blue–green emitting II–VI‐based monolithic microcavities

Abstract

AbstractIn this paper we review basic optical properties of II–VI‐based monolithic microcavities with quantum wells or quantum dots embedded. The epitaxial growth of high‐reflectivity distributed Bragg reflectors for the blue–green spectral range is discussed since they are a key component for micropillar cavities. The pillar structured samples reveal three‐dimensionally confined optical modes with high quality factors and small mode volumes making them appropriate to investigate cavity quantum electrodynamic effects. The II–VI material system is very promising for the utilization of this effect for technological applications due to the large exciton oscillator strength and carrier confinement. The theoretical methods needed to describe light–matter interaction in such systems is reviewed. For the quantum well based cavities single‐mode stimulated emission at near room temperature is realized. Furthermore, the relatively large cavity polariton stability makes it possible to observe polariton condensation in this kind of samples. For the quantum dot based microcavities a strong enhancement of the emission intensity for quantum dots being in spectral resonance with the cavity modes is observed. To realize the necessary spectral matching a target fine tuning can be achieved by temperature variation or by post fabrication focused ion beam milling. A pronounced enhancement of the spontaneous emission rate of quantum dots coupled to the discrete optical modes of the cavities is demonstrated by the occurrence of the Purcell effect. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)