Quantum key distribution over multicore fiber

TL;DR

This paper demonstrates the first quantum key distribution over multicore fiber, showing coexistence with classical data at high bandwidths with minimal performance loss, enabling secure communication in high-capacity fiber networks.

Contribution

It introduces the first experimental implementation of QKD over multicore fiber and analyzes its compatibility with high-bandwidth classical data transmission.

Findings

QKD can coexist with classical signals in multicore fiber with negligible degradation.

Classical data bandwidths beyond 1Tb/s can be supported alongside QKD.

Successful 53 km transmission demonstrates practical feasibility.

Abstract

We present the first quantum key distribution (QKD) experiment over multicore fiber. With space division multiplexing, we demonstrate that weak QKD signals can coexist with classical data signals launched at full power in a 53 km 7-core fiber, while showing negligible degradation in performance. Based on a characterization of intercore crosstalk, we perform additional simulations highlighting that classical data bandwidths beyond 1Tb/s can be supported with high speed QKD on the same fiber.