Analysis of detector performance in a gigahertz clock rate quantum key distribution system
Patrick J. Clarke, Robert John Collins, Philip A. Hiskett, María-José García-Martínez, Nils J. Krichel, Aongus McCarthy, Michael G. Tanner, John A. O’Connor, Chandra M. Natarajan, Shigehito Miki, Masahide Sasaki, Zhen Wang, Mikio Fujiwara, Ivan Rech, Massimo Ghioni, Angelo Gulinatti, Robert H. Hadfield, Paul D. Townsend, Gerald S. Buller · New Journal of Physics · 2011
We present a detailed analysis of a gigahertz clock rate environmentally robust phase-encoded quantum key distribution (QKD) system utilizing several different single-photon detectors, including the first implementation of an experimental resonant cavity thin-junction silicon single-photon avalanche diode. The system operates at a wavelength of 850 nm using standard telecommunications optical fibre. A general-purpose theoretical model for the performance of QKD systems is presented with reference to these experimental results before predictions are made about realistic detector developments in this system. We discuss, with reference to the theoretical model, how detector operating parameters can be further optimized to maximize key exchange rates.