Interferometry with Faraday mirrors for quantumcryptography
Hugo Zbinden, J.-D. Gautier, Nicolas Gisin, B. Hüttner, A. Muller, Wolfgang Tittel · Electronics Letters · 1997
Quantum cryptography over 23 km of installed telecommunications fibre using a novel interferometer with Faraday mirrors is presented. The interferometer needs no alignment nor polarisation control and features 99.8% fringe visibility. A secret key of 20 kbit length with an error rate of 1.35% for 0.1 photon per pulse was produced.