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arXiv · 1203.4323

2-GHz clock quantum key distribution over 260 km of standard telecom fiber

Shuang Wang·Wei Chen·Jun-Fu Guo·Zhen-Qiang Yin·Hong-Wei Li·Zheng Zhou·Guang-Can Guo·Zheng-Fu Han
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Abstract

We report a demonstration of quantum key distribution (QKD) over a standard telecom fiber exceeding 50 dB in loss and 250 km in length. The differential phase shift QKD protocol was chosen and implemented with 2 GHz system clock rate. By careful optimization of the 1-bit delayed Faraday-Michelson interferometer and the use of the super-conducting single photon detector (SSPD), we achieved a quantum bit error rate below 2% when the fiber length was no more than 205 km, and of 3.45% for the 260 km length fiber with 52.9 dB loss. We also improved the quantum efficiency of SSPD to obtain high key rate for 50 km length.

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Shuang Wang, Wei Chen, Jun-Fu Guo, Zhen-Qiang Yin, Hong-Wei Li, Zheng Zhou, Guang-Can Guo, Zheng-Fu Han. 2012-03-20. 2-GHz clock quantum key distribution over 260 km of standard telecom fiber. https://doi.org/10.1364/ol.37.001008

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