Silicon Single Photon Avalanche Diodes for Quantum Key Distribution

S. Cova, Alberto Tosi, Franco Zappa +1 more

Gerald S. Buller, Patrick J. Clarke, Robert John Collins

We present a general purpose theoretical model of single-photon detectors in quantum key distribution systems and apply it to an autonomous gigahertz clocked phase basis set system operating at a wavelength of 850 nm over a standard telecommunications fiber quantum channel. The system has been demonstrated using a variety of different singlephoton detectors, including thick and thin junction silicon single-photon avalanche photodiodes and the first implementation of a resonant cavity thin junction silicon single-photon avalanche diode. We show, by means of the theoretical model, how improvements to certain detector parameters can optimize key exchange rates.

Alexandr A. Filyaev, Anton Losev, Vladimir Zavodilenko +1 more

Subject of study. A noise parameter, such as an afterpulse effect, that occurs in indium-gallium arsenide/indium phosphide single-photon avalanche diodes when operated as part of a single-photon detector in quantum key distribution systems was investigated. The aim of this study was the analysis of indium-gallium arsenide/indium phosphide single-photon avalanche diode afterpulse effect estimation approaches for real-world quantum key distribution systems and the development of a measurement technique and model for estimating the afterpulse effect in indium-gallium arsenide/indium phosphide single-photon avalanche diodes. Method. For the experimental measurement of the afterpulse probability in indium-gallium arsenide/indium phosphide single-photon avalanche diodes, a special stand was used. All components of this stand are controlled by LabVIEW software. The developed model of afterpulse probability is based on the non-Markovian character of this effect. Main results. A measurement technique and probabilistic model were developed to estimate the afterpulse based on the recursive nature of this effect in indium-gallium arsenide/indium phosphide single-photon avalanche diodes. This makes it possible to estimate the true value of the afterpulse probability by reaction with a single triggering of a single-photon detector composed of indium-gallium arsenide/indium phosphide single-photon avalanche diodes. Analysis of approaches to estimating the afterpulse used in real-world quantum key distribution systems was performed. The advantages of the developed approach over the standard methods that do not take into account the non-Markov nature of the effect under consideration are demonstrated. Practical significance. The proposed approach was developed in the form of two models (simple and complex), which allows a compromise between the accuracy of calculations and their complexity for the application of such devices in quantum key distribution systems.

Darius Bunandar, Nicholas C. Harris, Zheshen Zhang +6 more

H. Kumano, Kimura Satoshi, Suemune Ikuo

Gerald S. Buller, Ryan E. Warburton, Saverio Pellegrini +5 more

The application of quantum key distribution (QKD) has raised particular demands for single-photon detectors. One of the most promising candidates at the low-loss optical fibre communications windows is the planar geometry InGaAs/InP single-photon avalanche diode. These detectors have been modelled, fabricated and characterised at 1.55 µm wavelength. Their performance in terms of single-photon detection efficiency, dark count rate, timing jitter and afterpulsing behaviour are reported and compared with the best commercially available, linear multiplication avalanche photodiodes operated in Geiger-mode. Their use in the application of QKD is discussed.