High-Speed Quantum Key Distribution Systems for Optical Fiber networks in campus and metro areas 1 Xiao Tang, Lijun Ma, Alan Mink, Tiejun Chang, Hai Xu, Oliver Slattery, Anastase Nakassis, Barry Hershman, David Su, and Ronald F. Boisvert Information Technology Laboratory National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899 xiao.tang@nist.gov ABSTRACT Complete high-speed quantum key distribution (QKD) systems over fiber networks for campus and metro areas have been developed at NIST. The systems include an 850-nm QKD system for a campus network, a 1310-nm QKD system for metro networks, and a 3-user QKD network and network manager. In this paper we describe the key techniques used to implement these systems, including polarization recovery, noise reduction, frequency up-conversion detection based on PPLN waveguide, custom high-speed data handling and network management. A QKD-secured video surveillance system has been used to experimentally demonstrate these systems. Keywords: Quantum Key Distribution, Detection time bin shift, Single photon detector, optical fiber communication. 1. INTRODUCTION Since 1984 when the idea of quantum key distribution (QKD) [1] was invented, a number of groups have successfully demonstrated experimental QKD systems. Many of these were described in a comprehensive review article [2]. Laboratory high-speed QKD technology has become sophisticated, and integrating them into existing networks is the next and crucial step for commercial application of QKD technology. Networks are commonly divided into three categories, (i) local area networks (LAN); (ii) metropolitan area networks (MAN) and (iii) wide area networks (WAN). The LAN, sometimes referred to as a campus area network, is a short distance network (usually <5 km) typically using a star/hub topology. For this type of network, mass produced hardware is deployed since low-cost is a significant consideration. MANs are geographically larger than LANs and usually cover a city area (<50 km). MANs are usually based on a ring or mesh network topology implemented with Wavelength Division Multiplexing (WDM) technology. A WAN, sometimes called a core network or long-haul network, covers a broad area linking metropolitan areas and crossing national boundaries (e.g., several hundreds km or longer). This type of network usually uses a mesh network topology and Dense WDM (DWDM) technology. Long distance and high throughput are the main requirements for this kind of network. We have developed several technologies to integrate QKD into these networks. For LANs, an 850-nm system is a good choice, since low-cost vertical cavity surface emitting lasers (VCSELs) and silicon-based avalanche photodiodes (APDs) work at this wavelength very well. Our 850-nm QKD system produces a key rate of more than 1 Mbit/s over 4 km of standard telecom fiber [3, 4]. To further reduce the cost and improve the security, we implemented a detection-time-bin- 1 The identification of any commercial product or trade name does not imply endorsement or recommendation by the National Institute of Standards and Technology. Quantum Communications and Quantum Imaging VI, edited by Ronald E. Meyers, Yanhua Shih, Keith S. Deacon, Proc. of SPIE Vol. 7092, 70920I, (2008) · 0277-786X/08/$18 · doi: 10.1117/12.793852 Proc. of SPIE Vol. 7092 70920I-1