Quantum key distribution (QKD) provides information-theoretic security based on the laws of quantum mechanics. The desire to reduce costs and increase robustness in real-world applications has motivated the study of coexistence between QKD and intense classical data traffic in a single fiber. Previous works on coexistence in metropolitan areas have used wavelength-division multiplexing, however, coexistence in backbone fiber networks remains a great experimental challenge, as Tbps data of up to 20 dBm optical power is transferred, and much more noise is generated for QKD. Here we present for the first time, to the best of our knowledge, the integration of QKD with a commercial backbone network of 3.6 Tbps classical data at 21 dBm launch power over 66 km fiber. With 20 GHz pass-band filtering and large effective core area fibers, real-time secure key rates can reach 4.5 kbps and 5.1 kbps for co-propagation and counter-propagation at the maximum launch power, respectively. This demonstrates feasibility and represents an important step towards building a quantum network that coexists with the current backbone fiber infrastructure of classical communications.
In-Line Fiber-Integrated Photon-Pair Generation from van der Waals Crystals
Agency for Science, Technology and Research (A*STAR)（新加坡科技研究局）；Department of Quantum Science and Technology, Research School of Physics and Engineering, Australian National University (ANU)（澳大利亚国立大学物理与工程研究学院量子科学与技术系）；Institute of Materials Research and Engineering (IMRE), A*STAR（新加坡科技研究局材料研究与工程学院）；Science, Mathematics, and Technology (SMT), Singapore University of Technology and Design（新加坡科技设计大学科学、数学与技术学部）；School of Engineering, College of System and Society, ANU（澳大利亚国立大学系统与社会学院工程学院）；Centre for Quantum Technologies (CQT), National University of Singapore（新加坡国立大学量子技术中心）
Multiplexing of Continuous-Variable and Discrete-Variable Quantum Key Distribution Systems over Fibered and Free-Space Channels
Università degli Studi di Padova（帕多瓦大学）；Padua Quantum Technologies Research Center, Università degli Studi di Padova（帕多瓦量子技术研究中心，帕多瓦大学）；Sorbonne Université, CNRS, LIP6（索邦大学，法国国家科学研究中心，LIP6实验室）；ONERA, DOTA, Paris Saclay University（法国航空国防研究院，DOTA部门，巴黎萨克雷大学）
High-rate quantum digital signatures over 250 km of optical fiber
Guangxi University（广西大学）；The 34th Research Institute of China Electronics Technology Group Corporation（中国电子科技集团公司第三十四研究所）；Ji Hua Laboratory（季华实验室）；Renmin University of China（中国人民大学）
Secure Medical Data Transmission Using Quantum Key Distribution and Post-Quantum Cryptography in Real-World Fiber Networks
Quantum Optics Jena GmbH（量子光学耶拿有限公司）；Institute of Applied Physics, Friedrich Schiller University Jena（耶拿弗里德里希·席勒大学应用物理研究所）；Max Planck School of Photonics, Friedrich Schiller University Jena（耶拿弗里德里希·席勒大学马克斯·普朗克光子学院）；University of Applied Sciences Nordhausen（诺德豪森应用技术大学）；Fraunhofer Institute for Applied Optics and Precision Engineering IOF（弗劳恩霍夫应用光学和精密工程研究所）
Fiber-optic quantum interface with an array of more than 100 individually addressable atoms on an optical nanofiber
Waseda University（早稻田大学）；National Institute of Information and Communications Technology（信息通信研究机构）；RIKEN Center for Quantum Computing (RQC), RIKEN（理化学研究所量子计算中心）
Quantum-enhanced physical-layer threat detection in metropolitan-scale fiber networks
The University of Texas at Austin（德克萨斯大学奥斯汀分校）；RTX BBN Technologies（RTX BBN科技公司）；University of California, San Diego（加利福尼亚大学圣地亚哥分校）；University of Maryland（马里兰大学）
High-rate continuous-variable quantum key distribution coexisting with Tb/s coherent classical transmission in hollow-core fiber
Huazhong University of Science and Technology（华中科技大学）；Yangtze Optica Fibre and Cable Joint Stock Limited Company (YOFC)（长飞光纤光缆股份有限公司）；Chalmers University of Technology（查尔姆斯理工大学）；University of Florence（佛罗伦萨大学）
