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Optics Express

Photon nonlinear mixing in subcarrier multiplexed quantum key distribution systems

J. Capmany

Published Apr 2, 2009• 10 citations
Publisher

Abstract

We provide, for the first time to our knowledge, an analysis of the influence of nonlinear photon mixing on the end to end quantum bit error rate (QBER) performance of subcarrier multiplexed quantum key distribution systems. The results show that negligible impact is to be expected for modulation indexes in the range of 2%.
DOI
10.1364/oe.17.006457

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The incorporation of multiplexing techniques used in microwave photonics to quantum key distribution (QKD) systems brings important advantages by enabling the simultaneous and parallel delivery of multiple keys between a central station and different end-users in the context of multipoint access and metropolitan networks, or by providing higher key distribution rates in point to point links by suitably linking the parallel distributed keys. It also allows the coexistence of classical information and QKD channels over a single optical fiber infrastructure. In this paper, we show, for the first time to our knowledge, the successful operation of a two-domain (subcarrier and wavelength division) multiplexed strong reference BB84 QKD system. A four-independent channel QKD system featuring a sifted key rate of 10 kb/s/channel over an 11-km link with quantum bit error rate (QBER)$<$2% is reported. These results open the way for multi-QKD over optical fiber networks.
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