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HL: Fachverband Halbleiterphysik
HL 16: Microcavities
HL 16.8: Talk
Monday, March 14, 2011, 16:30–16:45, FOE Anorg
Experimental realization of high-Q AlAs/GaAs micropillar cavities with submicrometer diameters — •Florian Dunzer1, Matthias Lermer1, Niels Gregersen2, Jesper Mørk2, Stephan Reitzenstein1, Sven Höfling1, Martin Kamp1, and Alfred Forchel1 — 1Technische Physik and Wilhelm Conrad Röntgen Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany — 2DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Building 343, DK-2800 Kongens Lyngby, Denmark
Quantum Dots (QDs) integrated in micropillar cavities with both high quality factors (Q) and small mode volumes (Vmode) constitute a promising class of solid-state quantum light sources. For instance, pronounced cavity quantum electrodynamics effects in the weak and strong QD-cavity coupling regime can be observed in these systems. A figure of merit for the observation of pronounced effects in the two regimes are the ratios Q/Vmode and Q/(sqrt(Vmode)), respectively. Q factors as high as 165,000 have been demonstrated for micropillars with large mode volume (Vmode>50(λ/n)) [1]. To reduce Vmode one might simply decrease the diameter (dc) of the pillars, yet resulting in a significant reduction of Q due to side wall scattering losses and mode mismatch. These effects limit Q to about 2,000 for dc<1 micrometer [2]. To overcome this problem, we have designed and implemented a novel AlAs/GaAs cavity design showing Q factors higher than 10,000 for micropillars with submicron diameters (Vmode<3.5(λ/n)).