Wang Bi-Xiao, Tang Shi-Biao, Mao Yingqiu, Xu Wenhua, Cheng Ming, Zhang Jun, Chen Teng-Yun, Pan Jian-Wei
Opt Express. 2021 Nov 8;29(23):38582-38590. doi: 10.1364/OE.442785.
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.
量子密钥分发（QKD）提供了一种信息理论上安全的方法，用于在合法用户之间共享密钥。为了实现QKD的大规模部署，它应该易于扩展且具有成本效益。量子接入网络（QAN）的基础设施建设扩大了网络容量，而QKD与经典光通信之间的集成降低了信道成本。在此，我们展示了一种基于10 Gbit/s以太网无源光网络（10G-EPON）的实用下行QAN，它可支持多达64个用户。在使用单馈线光纤结构的完全共存方案中，QAN和10G-EPON信号在21公里光纤上实现了9 dB衰减的共传播，16个用户中的每个用户的安全密钥率达到1.5 kbps。在使用双馈线光纤结构的部分共存方案中，QAN和全功率10G-EPON信号在11公里上实现了组合，网络容量为64用户。我们工作中基于10G-EPON的实用QAN朝着实现大规模QKD基础设施迈出了重要一步。
