In-field comparison between G.652 and G.655 optical fibres for polarisation-based quantum key distribution

Integration of Quantum Key Distribution (QKD) in existing telecommunication infrastructure is crucial for the widespread adoption of this quantum technology that offers the distillation of unconditionally secure keys between users. The authors report a field trial between the Points of Presence placed in Treviso and in Venezia—Mestre, Italy, exploiting the QuKy commercial polarisation-based QKD platforms developed by ThinkQuantum S.r.l. and two different standards of single-mode optical fibres, that is, G.652 and G.655 as a quantum channel. In this field trial, several configurations were tested, including the co-existence of classical and quantum signals over the same fibre, providing a direct comparison between the performances of the G.652 and G.655 fibre standards for QKD applications.