title: Characterization of fiber-generated entangled photon pairs with superconducting single-photon detectors.
abstract: We demonstrate the suitability of fiber-generated entangled photon pairs for practical quantum communications in the telecom band by measuring their properties with superconducting single-photon detectors that produce negligible dark counts. The photon pairs are created in approximately 5-ps duration windows at 50 MHz rate while the detectors are operated in ungated free running mode. We obtain a coincidence to accidental-coincidence ratio >80 with raw photon-counting data, i.e., without making any post-measurement corrections. Using a previously demonstrated counter-propagating scheme we also produce polarization-entangled photon pairs at 50-MHz rate, which in coincidence detection directly yield two-photon interference with a fringe visibility >98%.
authors.forename: Chuang
authors.initials: C
authors.lastname: Liang
authors.forename: Kim F
authors.initials: KF
authors.lastname: Lee
authors.forename: Milja
authors.initials: M
authors.lastname: Medic
authors.forename: Prem
authors.initials: P
authors.lastname: Kumar
authors.forename: Robert H
authors.initials: RH
authors.lastname: Hadfield
authors.forename: Sae W
authors.initials: SW
authors.lastname: Nam