Continuous high speed coherent one-way quantum key distribution
Damien Stucki, Claudio Barreiro, Sylvain Fasel, Jean-Daniel Gautier, Olivier Gay, Nicolas Gisin, Rob Thew, Yann Thoma, Patrick Trinkler, Fabien Vannel, Hugo Zbinden · Optics Express · 2009
Quantum key distribution (QKD) is the first commercial quantum technology operating at the level of single quanta and is a leading light for quantum-enabled photonic technologies. However, controlling these quantum optical systems in real world environments presents significant challenges. For the first time, we have brought together three key concepts for future QKD systems: a simple high-speed protocol; high performance detection; and integration both, at the component level and for standard fibre network connectivity. The QKD system is capable of continuous and autonomous operation, generating secret keys in real time. Laboratory and field tests were performed and comparisons made with robust InGaAs avalanche photodiodes and superconducting detectors. We report the first real world implementation of a fully functional QKD system over a 43 dB-loss (150 km) transmission line in the Swisscom fibre optic network where we obtained average real-time distribution rates over 3 hours of 2.5 bps.