Düsseldorf 2007 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 35: Poster Quantenkommunikation
Q 35.3: Poster
Dienstag, 20. März 2007, 16:30–18:30, Poster C
Optical free-space quantum key distribution — •Sebastian Schreiner1, Henning Weier1, Martin Fürst1, Tobias Schmitt-Manderbach2, Christian Kurtsiefer3, and Harald Weinfurter1,2 — 1Department für Physik der LMU München, Schellingstr 4/III, 80799 München — 2Max Planck Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching — 3Department of Physics, National University of Singapore, 2, Science Drive 3, Singapore 117542
Based on fundamental laws of quantum mechanics, it is possible to generate and to distribute cryptographic keys in a provable safe way. A potential eavesdropper will necessarily disturb the communication by his quantum measurement. This leads to an error rate in the generated keys which allows to evaluate an upper bound on the information eavesdropped.
Here we evaluate the performance of a down town demonstration system operating over a distance of about 500 m. It uses the BB84 protocol with polarized photons from attenuated laser pulses as qubits. The remote controlled system allows for continuous QKD and implements several design and electronic improvements. Furthermore with this new setup the utilization of decoy states as well as daylight operation shall be enabled. We report on experiments that investigate the limits of free-space transmission and discuss the requirements for the development of a compact, fully integrated QKD system.