Coauthors: Hannes Huebel Chris Erven Thomas Jennewein

This poster demonstrates how currently installed fibre optic cables can be used as a medium for Quantum Key Distribution, using photons of wavelength 810 nm. Though telecommunication fibres use photons near 1550 nm for minimal attenuation, single photon detectors at this wavelength are bulky and inefficient. We will show that telecom fibre can be used for 810 nm photons, where good sources and detectors exist. An existing free-space link at the University of Waterloo will be transformed to operate on a 2.2 km fibre optic connection between the University of Waterloo and the Perimeter Institute. The system will operate a full Quantum Key Distribution protocol, including time stamping and analysis to compensate for the dispersion of different modes in the fibre: using coincidence analysis software, one of the modes will be selected and used for Key Distribution. Thus it will be shown that any existing fibre optic network is a potential candidate for Quantum Key Distribution.