FPGA based digital phase-coding quantum key distribution system  

作　　者：LU XiaoMing Zhang LiJun WANG YongGang CHEN Wei HUANG DaJun LI Deng WANG Shuang HE DeYong YIN ZhenQiang ZHOU Yu HUI Cong HAN ZhengFu 

机构地区：[1]Department of Modern Physics, University of Science and Technology of China [2]Key Laboratory of Quantum Information, University of Science and Technology of China [3]Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Chinese Academy of Sciences

出　　处：《Science China(Physics,Mechanics & Astronomy)》2015年第12期153-159,共7页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Key Basic Research Program of China(Grant Nos.2011CBA00200 and 2011CB921200);the National Natural Science Foundation of China(Grant Nos.61201239,6120511811304397 and 61475148);the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant Nos.XDB01030100 and XDB01030300)

摘　　要：Quantum key distribution （QKD） is a technology with the potential capability to achieve information-theoretic security. Phase- coding is an important approach to develop practical QKD systems in fiber channel. In order to improve the phase-coding modulation rate, we proposed a new digital-modulation method in this paper and constructed a compact and robust prototype of QKD system using currently available components in our lab to demonstrate the effectiveness of the method. The system was deployed in laboratory environment over a 50 km fiber and continuously operated during 87 h without manual interaction. The quantum bit error rate （QBER） of the system was stable with an average value of 3.22% and the secure key generation rate is 8.91 kbps. Although the modulation rate of the photon in the derno system was only 200 MHz, which was limited by the Faraday- Michelson interferometer （FMI） structure, the proposed method and the field programmable gate array （FPGA） based electronics scheme have a great potential for high speed QKD systems with Giga-bits/second modulation rate.Quantum key distribution(QKD) is a technology with the potential capability to achieve information-theoretic security. Phasecoding is an important approach to develop practical QKD systems in fiber channel. In order to improve the phase-coding modulation rate, we proposed a new digital-modulation method in this paper and constructed a compact and robust prototype of QKD system using currently available components in our lab to demonstrate the effectiveness of the method. The system was deployed in laboratory environment over a 50 km fiber and continuously operated during 87 h without manual interaction. The quantum bit error rate(QBER) of the system was stable with an average value of 3.22% and the secure key generation rate is 8.91 kbps. Although the modulation rate of the photon in the demo system was only 200 MHz, which was limited by the FaradayMichelson interferometer(FMI) structure, the proposed method and the field programmable gate array(FPGA) based electronics scheme have a great potential for high speed QKD systems with Giga-bits/second modulation rate.

关 键 词：quantum key distribution phase-coding digital phase modulation field programmable gate array Faraday-Michelsoninterferometer 

分 类 号：O413[理学—理论物理] TN918.4[理学—物理]