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Experimental Study of High Speed Polarization -Coding Quantum Key Distribution with Sifted -Key Rates Over Mbit/s



Xiao Tang, Lijun Ma, Alan Mink, Anastase Nakassis, Barry J. Hershman, Joshua C. Bienfang, David H. Su, Ronald F. Boisvert, Charles W. Clark, Carl J. Williams


We have demonstrated a polarization encoded, fiber-based quantum key distribution system operating at 850 nm in the B92 protocol. With a quantum bit transmission rate i.e. optical pulse driving frequency of 625 MHz and a mean photon number of 0.1, we achieved a sifted-key rate of 2.09 Mbit/s over 1 km optical fiber. The quantum bit error rate is 3.2%. After error collection and privacy amplification a net key rate of 1.7 Mbit/s is obtained. That is sufficient for one-time-pad encryption of streaming video. Moreover, we studied various limitations for higher speed quantum key distribution systems. The results show that the dead time of the Silicon Avalanche Photo Diodes limits the possible sifted-key rate if one does not consider the error rate. The timing jitters in the system, particularly the data-dependent part of the jitter, limits the quantum bit error rate and thus prevent the generation of higher sifted-key rate.
Optics Express


fiber optics communications, optical communication, photon counting, polarization-maintaining, quantum detectors


Tang, X. , Ma, L. , Mink, A. , Nakassis, A. , Hershman, B. , Bienfang, J. , Su, D. , Boisvert, R. , Clark, C. and Williams, C. (2009), Experimental Study of High Speed Polarization -Coding Quantum Key Distribution with Sifted -Key Rates Over Mbit/s, Optics Express, [online], (Accessed June 19, 2024)


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Created June 1, 2009, Updated February 19, 2017