Quantum Metrology with Two Colours and Fibre Sources
Brian Bell, Sathya Kannan, Alex R. McMillan, Alex S. Clark, W. J. Wadsworth, John Rarity · 2012
Four-wave mixing in photonic crystal fibre is used to generate path-entangled states of photons of two colours, and demonstrate interference fringes oscillating at 2, 4, and 6 times the frequency of the classical pump laser.