Generation of correlated photons via four-wave mixing in optical fibres

Correlated photons have been used in quantum optics for the generation of squeezed light, demonstration of quantum interference effects, quantum cryptography, Einstein-Podolsky-Rosen experiments and most recently, quantum teleportation. Usually, they are generated using χ⁽²⁾ parametric processes to take advantage of large χ⁽²⁾ nonlinearities and to wavelength separate the correlated photons from the pump photons. Here, we examine the generation of correlated photons using χ⁽³⁾ parametric processes in optical fibres. We show that using such processes provides a simple and inexpensive correlated photon source readily compatible with communications technologies.