title: Generation of high-purity entangled photon pair in a short highly nonlinear fiber.
abstract: We generate photon pairs at telecom wavelength through a spontaneous four-wave mixing process in a short 10 m of highly nonlinear fiber. We use a counterpropagating scheme to generate a correlated and entangled photon pair. We observe coincidence to accidental-coincidence ratio of 29±3 at room temperature (300 K) and as high as 130±5 when the fiber is cooled to liquid-nitrogen temperature (77 K). Two-photon interference with visibility >98% (>92%) and the violation of Bell's inequality by >12 (≈5) standard deviation are observed at 77 K (300 K), respectively, without subtracting accidental-coincidence count. We obtain a photon-pair production rate about factor 3(2) higher than a 300 m dispersion-shifted fiber at 300 K (77 K).
authors.affiliation: Department of Physics, Michigan Technological University, Houghton, Michigan 49931, USA.
authors.forename: Yong Meng
authors.initials: YM
authors.lastname: Sua
authors.forename: John
authors.initials: J
authors.lastname: Malowicki
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hirano
authors.forename: Kim Fook
authors.initials: KF
authors.lastname: Lee