Fully automated entanglement-based quantum cryptography system for telecom fiber networks

Author(s): A. Treiber, A. Poppe, M. Hentschel, D. Ferrini, T. Lorünser, E. Querasser, T. Matyus, H. Hübel, A. Zeilinger

Journal: New Journal of Physics

Volume: 11

Page(s): 045013

Year: 2009

DOI Number: 10.1088/1367-2630/11/4/045013

Link: Link to publication


We present in this paper a quantum key distribution (QKD) system based on polarization entanglement for use in telecom fibers. A QKD exchange up to 50 km was demonstrated in the laboratory with a secure key rate of 550 bits s−1. The system is compact and portable with a fully automated start-up, and stabilization modules for polarization, synchronization and photon coupling allow hands-off operation. Stable and reliable key exchange in a deployed optical fiber of 16 km length was demonstrated. In this fiber network, we achieved over 2 weeks an automatic key generation with an average key rate of 2000 bits s−1 without manual intervention. During this period, the system had an average entanglement visibility of 93%, highlighting the technical level and stability achieved for entanglement-based quantum cryptography.

Note: http://arxiv.org/abs/0901.2725

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