A stable long-distance quantum key distribution system

作者：Wu G; Zhou CY; Chen XL; Han XH; Zeng HP^*

来源：Acta Physica Sinica, 2005, 54(8): 3622-3626.

• quantum cryptography
• quantum key distribution
• single-photon detection

A stable long-distance quantum key distribution system which has been just completed in our laboratory is demonstrated in this paper. The idea of "plug and play" was adopted to automatically compensate the polarization mode dispersion and phase shift. A symmetrical capacitance-balance technique and magic-T network were used in the single-photon detection module, wherein a detection efficiency of more than 5% and a dark count probability of lower than 2.9 x 10(-6)/pulse were achieved. As a result, we have realized stable (longer than 12 h) quantum key distribution experiment in 50.6 km single mode fiber with mean photon number of 0.07 and quantum bit error rate of 4%.

• 出版日期2005-8
• 单位华东师范大学