M. Avesani, G. Foletto, M. Padovan, L. Calderaro, C. Agnesi, E. Bazzani, F. Berra, T. Bertapelle, F. Picciariello, F. B.L. Santagiustina, D. Scalcon, A. Scriminich, A. Stanco, F. Vedovato, G. Vallone, and P. Villoresi
J. Light. Technol. 40 (6), 1658 - 1663 (2022)
DOI:10.1109/JLT.2021.3130447

Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova, Italy

Current technological progress is driving Quantum Key Distribution towards a commercial and world widescale expansion. Its capability to deliver unconditionally secure communication will be a fundamental feature in the next generations of telecommunication networks. Nevertheless, demonstrations of QKD implementation in a real operating scenario and their coexistence with the classical telecom infrastructure are of fundamental importance for reliable exploitation. Here we present a Quantum Key Distribution application implemented overa classical fiber-based infrastructure. By exploiting just a single fiber cable for both the quantum and the classical channel and by using a simplified receiver scheme with just one single-photon detector, we demonstrate the feasibility of low-cost and ready-to-use Quantum Key Distribution systems compatible with standard classical infrastructure.