Photonic crystal fibre sources of correlated photon pairs

The paper reviews a new source of time-correlated photon pairs based on phase matched four-wave mixing in an optical fiber. This source has the potential to replace sources based on a non-linear birefringent crystals and waveguides. It generates linear polarised photon pairs in a narrow bandwidth, single circular mode which can be efficiently coupled into single mode fibres. We generate the parametric gain by pumping with a laser wavelength slightly below the zero dispersion wavelength, in the normal dispersion regime.