Employing long fibre-optical Mach-Zehnder interferometers for quantum cryptography with orthogonal states

G. B. Xavier, G. P. Temporao and J. P. von der Weid


It is experimentally demonstrated that a long distance actively stabilised Mach-Zehnder fibre optical interferometer can be used to reliably implement the GV95 quantum cryptography protocol employing orthogonal states. A proof-of-principle experiment using an interferometer composed of 1 km of spooled optical fibres connecting Alice and Bob is performed. The active stabilisation against phase drifts is done with a classical channel wavelength-multiplexed with the quantum channel and a highly stable visibility implying a quantum bit error rate of 2.2 % is shown.

DOI: http://dx.doi.org/10.1049/el.2012.0850

Categories: Publications