Abstract

We report what we believe to be the first differential-phase quantum key distribution experiment using a series of quantum entangled photon pairs. We employed two outstanding techniques. As an entangled photon source, we used a $1.5\mu \mathrm{m}$ band entangled photon pair source based on spontaneous four-wave mixing in a cooled dispersion-shifted fiber. As receivers, photon pairs were actively phase modulated with $\mathrm{Li}\mathrm{Nb}{\mathrm{O}}_3$ phase modulators followed by very stable planar light-wave circuit Mach–Zehnder interferometers, which provided two nonorthogonal measurements. As a consequence, we successfully generated sifted keys with a quantum bit error rate of 8.3% and a key generation rate of $0.3\text{\hspace{0.17em} bit}∕\mathrm{s}$ and revealed the feasibility of this QKD scheme.

© 2007 Optical Society of America

Long-distance entanglement-based quantum key distribution over optical fiber

T. Honjo, S. W. Nam, H. Takesue, Q. Zhang, H. Kamada, Y. Nishida, O. Tadanaga, M. Asobe, B. Baek, R. Hadfield, S. Miki, M. Fujiwara, M. Sasaki, Z. Wang, K. Inoue, and Y. Yamamoto
Opt. Express 16(23) 19118-19126 (2008)

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Opt. Express 18(16) 16777-16787 (2010)

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