Berlin 2018 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 55: Quantum dots and wires: Preparation and characterization

HL 55.7: Talk

Friday, March 16, 2018, 11:15–11:30, A 151

Wet chemical etching of optical microstructures in gallium arsenide to enhance the extraction efficiency of InAs quantum dots — •Lena Engel, Marc Sartison, Sascha Kolatschek, Stefan Hepp, Simone Portalupi, Michael Jetter, and Peter Michler — Institut für Halbleiteroptik und Funktionelle Grenzflächen, Center for Integrated Quantum Science and Technology (IQST) and SCoPE, University of Stuttgart, Allmandring 3, 70569 Stuttgart

Semiconductor quantum dots (QDs) have proven to be well-defined, pure and efficient single-photon sources. They have shown to be promising candidates for various applications such as quantum communication or quantum computing. One prerequisite for these applications in free-space or fiber-based quantum information is high brightness. As the emitters are embedded in a semiconductor environment, the extraction efficiency is strongly limited. In contrast to narrow band cavity quantum electrodynamic systems like micro pillars or photonic crystal cavities, we investigate a broadband approach, introducing wet chemically etched hemispheric and Gaussian micro lenses precisely aligned on a single emitter. The QDs are optically pre-selected, marked via in-situ lithography and formed by a following wet chemical etching step. This wet chemical approach results in a superior surface quality, which enables us to perform quantum optical experiments on optically resonant excited QDs with enhanced extraction efficiency. According to FDTD simulations, hemispheric and Gaussian micro lens geometries also show promising enhancement factors.