title: Metropolitan all-pass and inter-city quantum communication network.
abstract: We have demonstrated a metropolitan all-pass quantum communication network in field fiber for four nodes. Any two nodes of them can be connected in the network to perform quantum key distribution (QKD). An optical switching module is presented that enables arbitrary 2-connectivity among output ports. Integrated QKD terminals are worked out, which can operate either as a transmitter, a receiver, or even both at the same time. Furthermore, an additional link in another city of 60 km fiber (up to 130 km) is seamless integrated into this network based on a trusted relay architecture. On all the links, we have implemented protocol of decoy state scheme. All of necessary electrical hardware, synchronization, feedback control, network software, execution of QKD protocols are made by tailored designing, which allow a completely automatical and stable running. Our system has been put into operation in Hefei in August 2009, and publicly demonstrated during an evaluation conference on quantum network organized by the Chinese Academy of Sciences on August 29, 2009. Real-time voice telephone with one-time pad encoding between any two of the five nodes (four all-pass nodes plus one additional node through relay) is successfully established in the network within 60 km.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Teng-Yun
authors.initials: TY
authors.lastname: Chen
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Hao
authors.initials: H
authors.lastname: Liang
authors.forename: Wei-Yue
authors.initials: WY
authors.lastname: Liu
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiao
authors.initials: X
authors.lastname: Jiang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Xu
authors.initials: X
authors.lastname: Wan
authors.forename: Wei-Qi
authors.initials: WQ
authors.lastname: Cai
authors.forename: Lei
authors.initials: L
authors.lastname: Ju
authors.forename: Luo-Kan
authors.initials: LK
authors.lastname: Chen
authors.forename: Liu-Jun
authors.initials: LJ
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.forename: Cheng-Zhi
authors.initials: CZ
authors.lastname: Peng
authors.forename: Zeng-Bing
authors.initials: ZB
authors.lastname: Chen
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Pan
mesh_terms: D002947:Cities; D003195:Computer Communication Networks / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D011789:Quantum Theory; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*