title: Bright source of spectrally uncorrelated polarization-entangled photons with nearly single-mode emission.
abstract: We present results of a bright polarization-entangled photon source operating at 1552 nm via type-II collinear degenerate spontaneous parametric down-conversion in a periodically poled potassium titanyl phosphate crystal. We report a conservative inferred pair generation rate of 123,000 pairs/s/mW into collection modes. Minimization of spectral and spatial entanglement was achieved by group velocity matching the pump, signal, and idler modes and through properly focusing the pump beam. By utilizing a pair of calcite beam displacers, we are able to overlap photons from adjacent down-conversion processes to obtain polarization-entanglement visibility of 94.7+/-1.1% with accidentals subtracted.
authors.affiliation: Center for Quantum Information Science, Computing and Computational Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. evanspg@ornl.gov
authors.forename: P G
authors.initials: PG
authors.lastname: Evans
authors.forename: R S
authors.initials: RS
authors.lastname: Bennink
authors.forename: W P
authors.initials: WP
authors.lastname: Grice
authors.forename: T S
authors.initials: TS
authors.lastname: Humble
authors.forename: J
authors.initials: J
authors.lastname: Schaake