Open AccessField trial of differential-phase-shift quantum key distribution using polarization independent frequency up-conversion detectors
Author(s) -
Toshimori Honjo,
Shuto Yamamoto,
Takashi Yamamoto,
H. Kamada,
Y. Nishida,
O. Tadanaga,
Masaki Asobe,
Kyo Inoue
Publication year - 2007
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.15.015920
Subject(s) - quantum key distribution , detector , optics , differential phase , polarization (electrochemistry) , physics , key generation , computer science , electronic engineering , phase (matter) , photon , quantum mechanics , algorithm , chemistry , engineering , cryptography
We report a field trial of differential phase shift quantum key distribution (QKD) using polarization independent frequency up-conversion detectors. A frequency up-conversion detector is a promising device for achieving a high key generation rate when combined with a high clock rate QKD system. However, its polarization dependence prevents it from being applied to practical QKD systems. In this paper, we employ a modified polarization diversity configuration to eliminate the polarization dependence. Applying this method, we performed a long-term stability test using a 17.6-km installed fiber. We successfully demonstrated stable operation for 6 hours and achieved a sifted key generation rate of 120 kbps and an average quantum bit error rate of 3.14 %. The sifted key generation rate was not the estimated value but the effective value, which means that the sifted key was continuously generated at a rate of 120 kbps for 6 hours.