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Quantum Key Distribution (QKD) Multiplexing by Using the Attenuation Method

Ondřej Klíčník, Petr Münster, Tomáš Horváth

Published Jan 1, 2024• 0 citations
Publisher

Abstract

In this paper a novel approach to multiplexing quantum and classical channels into a single fiber is presented. A so-called attenuation method is used, that is mainly fo-cused on suppressing the influence of Raman noise.
DOI
10.1364/cleo_at.2024.aw3d.4

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The primary goal in this paper is to verify the possibility of combining a quantum channel into a single optical fiber with other classical channels by using the so-called attenuation method. Since the quantum channel is very weak in terms of power, combining it into a single fiber with much more powerful classical channels is challenging. Thus, sufficiently high-quality filtering is important to avoid possible crosstalk. A second and more difficult problem to address is the interference caused by Raman noise, which increases with the fiber length and is also dependent on the input power of the classical channel. Thus, in this paper the focus is on the possibility of suppressing the Raman noise effect, both in advance by means of wavelength positioning and by means of installed optical components. Such phenomena must be considered in the route design, as the quantum channel must be placed at a suitable wavelength with respect to the classical channels. The influence of other nonlinear phenomena has been neglected. In this paper, a practical experiment aimed at building a fully functional multiplexed quantum key distribution link is also described.
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