A short wavelength GigaHertz clocked fiber-optic quantum key distribution system

Abstract

Abstract-A quantum key distribution system has been developed, using standard telecommunications optical fiber, which is capable of operating at clock rates of greater than 1 GHz. The quantum key distribution system implements a polarization encoded version of the B92 protocol. The system employs vertical-cavity surface-emitting lasers with emission wavelengths of 850 nm as weak coherent light sources, and silicon single photon avalanche diodes as the single photon detectors. A distributed feedback laser of emission wavelength 1.3 µ µ µ µm, and a linear gain germanium avalanche photodiode was used to optically synchronize individual photons over the standard telecommunications fiber. The quantum key distribution system exhibited a quantum bit error rate of 1.4%, and an estimated net bit rate greater than 100,000 bits -1 for a 4.2 km transmission range. For a 10 km fiber range a quantum bit error rate of 2.1%, and estimated net bit rate of greater than 7,000 bits -1 was achieved.

Design and Performance of an InGaAs–InP Single-Photon Avalanche Diode Detector

“…More recently they have been employed in quantum key distribution [4] and noninvasive testing of VLSI circuits [5]. Commercially available InGaAs-InP avalanche photodiodes (APDs) designed for use in linear multiplication mode have been tested in Geiger mode [6], [7] in order to extend the spectral range of efficient single-photon detection to wavelengths greater than that afforded by the currently available Si-based single-photon avalanche diode (SPAD) detectors (i.e., wavelengths greater than 1 m).…”

An Application of Quantum Networks for Secure Video Surveillance

“…4(a), and be erroneously detected causing an increase in the QBER. Fusion splicing a short piece of HI780 fiber to the end of the SMF-28 fiber functions as a spatial filter and partially filters the higher order mode pulse [Townsend, 1998;Gordon, et al, 2004], see Fig. 4(b), allowing the 850 nm quantum channel to successfully coexist with 1550 nm traffic on standard telecom fiber.…”

Network Architectures for QKD

“…Recent demonstrations have illustrated the feasibility of quantum key distribution (QKD) over conventional optical telecommunications hardware [4]- [6], and even through sufficiently transparent photonic switching devices [7]. The next step in the evolution of QKD systems is likely to involve networks that offer more than simple point-to-point communications pathways.…”