Abstract

Photon pairs generated in the process of spontaneous parametric down-conversion are commonly used in implementations of quantum communication protocols, proof-of-principle demonstrations of quantum computing circuitry, and other realisations of emerging quantum technologies [1]. Bulk sources of photon pairs based on χ⁽²⁾ nonlinear media typically suffer from low conversion rates and poor coupling efficiencies owing to the complicated spatial structure of the generated light. Nonlinear fibres and waveguides offer a potential solution to these issued by restricting the modal structure at the generation stage, opening at the same time new routes towards engineering spatial entanglement [2].

© 2013 IEEE