High-rate 16-node quantum access network based on a passive optical network

Quantum key distribution offers information-theoretic security and is advancing toward real-world quantum secure networks. To meet the growing demand for scalable solutions, we present a high-rate quantum access network (QAN) with 16 user nodes based on a passive optical network, where a highly efficient coherent-state point-to-multipoint (PTMP) protocol is designed for concurrent independent secret key generation between one transmitter and multiple receivers. Such accomplishment is attributed to a subtle shot-noise calibration method, advanced digital signal processing algorithms, and a flexible post-processing strategy. Finally, the experimentally estimated average secret key rate is approximately 2.086 Mbps between the transmitter and each user, two orders of magnitude higher than previous demonstrations. With low cost, excellent compatibility, and wide bandwidth, our work paves the way for practical PTMP QANs, representing a key step toward scalable quantum secure networks.