Photonic integrated circuits hold great promise in enabling the practical wide-scale deployment of quantum communications; however, despite impressive experiments of component functionality, a fully operational quantum communication system using photonic chips is yet to be demonstrated. Here we demonstrate an entirely standalone secure communication system based on photonic integrated circuits—assembled into compact modules—for quantum random number generation and quantum key distribution at gigahertz clock rates. The bit values, basis selection and decoy pulse intensities used for quantum key distribution are chosen at random, and are based on the output of a chip-based quantum random number generator operating at 4 Gb s^–1. Error correction and privacy amplification are performed in real time to produce information-theoretic secure keys for a 100 Gb s^–1 line speed data encryption system. We demonstrate long-term continuous operation of the quantum secured communication system using feedback controls to stabilize the qubit phase and propagation delay over metropolitan fibre lengths. These results mark an important milestone for the realistic deployment of quantum communications based on quantum photonic chips.

光子集成电路在实现量子通信的实际大规模部署方面具有很大的前景；然而，尽管对组件功能进行了令人印象深刻的实验，但使用光子芯片的完全可操作的量子通信系统仍有待证明。在这里，我们展示了一个基于光子集成电路的完全独立的安全通信系统——组装成紧凑的模块——用于以千兆赫时钟速率生成量子随机数和量子密钥分发。用于量子密钥分发的比特值、基础选择和诱饵脉冲强度是随机选择的，并且基于以 4 Gb s ^{–1运行的基于芯片的量子随机数发生器的输出}. 实时执行纠错和隐私放大，为 100 Gb s ^–1线速数据加密系统生成信息论安全密钥。我们演示了量子安全通信系统的长期连续运行，该系统使用反馈控制来稳定城域光纤长度上的量子比特相位和传播延迟。这些结果标志着基于量子光子芯片的量子通信实际部署的重要里程碑。