Hannover 2010 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 25: Quantum Information: Quantum Communication I
Q 25.1: Talk
Wednesday, March 10, 2010, 10:30–10:45, E 214
Atmospheric quantum communication with continuous polarization variables — •Bettina Heim1,2, Dominique Elser1,2, Claudia Dürr1,2,3, Tim Bartley1,2,4, Christoffer Wittmann1,2, Denis Sych1,2, Christoph Marquardt1,2, and Gerd Leuchs1,2 — 1Max-Planck-Institut für die Physik des Lichts, Erlangen — 2Institut für Optik, Information und Photonik, Universität Erlangen-Nürnberg — 3Hochschule für Angewandte Wissenschaften - FH München — 4Clarendon Laboratory, University of Oxford
We present experimental work on the demonstration of free space quantum communication using continuous polarization variables. In a prepare-and-measure setup, binary-encoded coherent polarization states are transmitted through an atmospheric quantum channel of 100m. The signal states are measured using homodyne detection with the help of a local oscillator (LO) occupying the same spatial mode as the signal. Thus, the interference of signal and LO is excellent. Additionally, the LO acts as spatial and spectral filter, which allows for unrestrained daylight operation. Currently, we are working on expanding the link distance to 1.6km in an urban environment. Influences of the turbulent atmosphere resulting in spatial beam jitter could cause attenuation as well as intensity noise at the detector [1]. We investigate these potentially harmful effects and present methods to compensate for them.
[1] B. Heim et al., Applied Physics B, published online
http://dx.doi.org/10.1007/s00340-009-3838-8