Practical quantum access network over a 10 Gbit/s Ethernet passive optical network

TL;DR

This paper demonstrates a practical quantum access network integrated with a 10 Gbit/s Ethernet passive optical network supporting up to 64 users, achieving secure key distribution over significant distances, advancing large-scale QKD deployment.

Contribution

It presents a scalable, cost-effective quantum access network compatible with existing Ethernet infrastructure, supporting multiple users over long distances with practical secure key rates.

Findings

Supports 64 users with quantum key distribution over 21 km fiber in full coexistence scheme.

Achieves a secure key rate of 1.5 kbps per user in the full coexistence scheme.

Demonstrates coexistence of QAN and classical signals over 11 km fiber in dual feeder fiber structure.

Abstract

Quantum key distribution (QKD) provides an information-theoretically secure method to share keys between legitimate users. To achieve large-scale deployment of QKD, it should be easily scalable and cost-effective. The infrastructure construction of quantum access network (QAN) expands network capacity and the integration between QKD and classical optical communications reduces the cost of channel. Here, we present a practical downstream QAN over a 10 Gbit/s Ethernet passive optical network (10G-EPON), which can support up to 64 users. In the full coexistence scheme using the single feeder fiber structure, the co-propagation of QAN and 10G-EPON signals with 9 dB attenuation is achieved over 21 km fiber, and the secure key rate for each of 16 users reaches 1.5 kbps. In the partial coexistence scheme using the dual feeder fiber structure, the combination of QAN and full-power 10G-EPON signals is achieved over 11 km with a network capacity of 64-user. The practical QAN over the 10G-EPON in our work implements an important step towards the achievement of large-scale QKD infrastructure.