Regensburg 2007 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 44: Semiconductor Microcavities and Entangled States in Quantum Dots

HL 44.5: Invited Talk

Thursday, March 29, 2007, 16:15–16:45, H15

Optical Semiconductor Microtube Ring Cavities — •Tobias Kipp, Christian Strelow, Holger Welsch, Hagen Rehberg, Christoph M. Schultz, Christian Heyn, and Detlef Heitmann — Institute of Applied Physics, University of Hamburg, Germany

Recently we demonstrated that self-supporting microtubes can act as novel kinds of optical microcavites [1]. These microtubes are fabricated, starting from an epitaxially grown InGaAs/GaAs bilayer and using optical lithography and wet-etching processes, by utilizing the self-rolling mechanism of strained bilayers. The diameters of these microtubes are typically about 5 µm, whereas their walls are only 50-200 nm thick. We incorporate either self-assembled quantum dots or quantum wells as optically active material inside the tube walls. In photoluminescence spectra we find in both cases sharp modes arising from constructive interference of light running around the microtube’s axis. The mode structure is in very good agreement to theoretical calculations, modelling the microtube as a closed dielectric waveguide. We discuss possibilities and show evidences of a three-dimensional confinement of light in these novel microtube ring cavities

We gratefully acknowledge financial support of the Deutsche Forschungsgemeinschaft via the SFB 508 and the Graduiertenkolleg 1286.

[1] T. Kipp et al., PRL 96, 077403 (2006).