title: Tailored photon-pair generation in optical fibers.
abstract: We experimentally control the spectral structure of photon pairs created via spontaneous four-wave mixing in microstructured fibers. By fabricating fibers with designed dispersion, one can manipulate the photons' wavelengths, joint spectrum, and, thus, entanglement. As an example, we produce photon pairs with no spectral correlations, allowing direct heralding of single photons in pure-state wave packets without filtering. We achieve an experimental purity of (85.9+/-1.6)%, while theoretical analysis and preliminary tests suggest that 94.5% purity is possible with a much longer fiber.
authors.affiliation: Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, UK. o.cohen1@physics.ox.ac.uk
authors.forename: Offir
authors.initials: O
authors.lastname: Cohen
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Lundeen
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Smith
authors.forename: Graciana
authors.initials: G
authors.lastname: Puentes
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Mosley
authors.forename: Ian A
authors.initials: IA
authors.lastname: Walmsley