TY  - JOUR
A1  - Amthor, Matthias
A1  - Weißenseel, Sebastian
A1  - Fischer, Julian
A1  - Kamp, Martin
A1  - Schneider, Christian
A1  - Höfling, Sven
T1  - Electro-optical switching between polariton and cavity lasing in an InGaAs quantum well microcavity
N2  - We report on the condensation of microcavity exciton polaritons under optical excitation in a microcavity with four embedded InGaAs quantum wells. The polariton laser is characterized by a distinct nonlinearity in the input-output-characteristics, which is accompanied by a drop of the emission linewidth indicating temporal coherence and a characteristic persisting emission blueshift with increased particle density. The temporal coherence of the device at threshold is underlined by a characteristic drop of the second order coherence function to a value close to 1. Furthermore an external electric field is used to switch between polariton regime, polariton condensate and photon lasing.
KW  - Quantum-well, -wire and -dot devices
KW  - Scattering
KW  - stimulated
KW  - Resonators
KW  - Microcavity devices
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111130
ER  - 
TY  - JOUR
A1  - Maier, Sebastian
A1  - Gold, Peter
A1  - Forchel, Alfred
A1  - Gregersen, Niels
A1  - Mork, Jesper
A1  - Höfling, Sven
A1  - Schneider, Christian
A1  - Kamp, Martin
T1  - Bright single photon source based on self-aligned quantum dot-cavity systems
JF  - Optics Express
N2  - We report on a quasi-planar quantum-dot-based single-photon source that shows an unprecedented high extraction efficiency of 42% without complex photonic resonator geometries or post-growth nanofabrication. This very high efficiency originates from the coupling of the photons emitted by a quantum dot to a Gaussian shaped nanohill defect that naturally arises during epitaxial growth in a self-aligned manner. We investigate the morphology of these defects and characterize the photonic operation mechanism. Our results show that these naturally arising coupled quantum dot-defects provide a new avenue for efficient (up to 42% demonstrated) and pure (g(2)(0) value of 0.023) single-photon emission.
KW  - photon statistics
KW  - quantum communications
KW  - resonators
KW  - quantum-well -wire and -dot devices
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119801
SN  - 1094-4087
VL  - 22
IS  - 7
ER  - 
TY  - JOUR
A1  - Rau, Markus
A1  - Heindel, Tobias
A1  - Unsleber, Sebastian
A1  - Braun, Tristan
A1  - Fischer, Julian
A1  - Frick, Stefan
A1  - Nauerth, Sebastian
A1  - Schneider, Christian
A1  - Vest, Gwenaelle
A1  - Reitzenstein, Stephan
A1  - Kamp, Martin
A1  - Forchel, Alfred
A1  - Höfling, Sven
A1  - Weinfurter, Harald
T1  - Free space quantum key distribution over 500 meters using electrically driven quantum dot single-photon sources-a proof of principle experiment
JF  - New Journal of Physics
N2  - Highly efficient single-photon sources (SPS) can increase the secure key rate of quantum key distribution (QKD) systems compared to conventional attenuated laser systems. Here we report on a free space QKD test using an electrically driven quantum dot single-photon source (QD SPS) that does not require a separate laser setup for optical pumping and thus allows for a simple and compact SPS QKD system. We describe its implementation in our 500 m free space QKD system in downtown Munich. Emulating a BB84 protocol operating at a repetition rate of 125 MHz, we could achieve sifted key rates of 5-17 kHz with error ratios of 6-9% and g((2))(0)-values of 0.39-0.76.
KW  - QKD
KW  - electrically driven
KW  - free space
KW  - quantum dots
KW  - quantum key distribution
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116760
VL  - 16
IS  - 043003
ER  -