title: Generation of high-purity telecom-band entangled photon pairs in dispersion-shifted fiber.
abstract: We study the purity of correlated photon pairs generated in a dispersion-shifted fiber at various temperatures. The ratio of coincidence to accidental-coincidence counts greater than 100 can be obtained as the fiber is cooled to liquid-nitrogen temperature (77 K). We then generate polarization-entangled photon pairs by using a compact counterpropagating scheme. Two-photon interference with visibility >98% and Bell's inequality violation by >8 standard deviations of measurement uncertainty are observed at 77 K, without subtracting the accidental-coincidence counts due to background Raman photons.
authors.affiliation: Department of Electrical Engineering and Computer Science, Center for Photonic Communication and Computing, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA. kflee@ece.northwestern.edu
authors.forename: Kim Fook
authors.initials: KF
authors.lastname: Lee
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Chuang
authors.initials: C
authors.lastname: Liang
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Li
authors.forename: Paul L
authors.initials: PL
authors.lastname: Voss
authors.forename: Prem
authors.initials: P
authors.lastname: Kumar