title: Heralded single-photon source utilizing highly nondegenerate, spectrally factorable spontaneous parametric downconversion.
abstract: We report on the generation of an indistinguishable heralded single-photon state, using highly nondegenerate spontaneous parametric downconversion (SPDC). Spectrally factorable photon pairs can be generated by incorporating a broadband pump pulse and a group-velocity matching (GVM) condition in a periodically-poled potassium titanyl phosphate (PPKTP) crystal. The heralding photon is in the near IR, close to the peak detection efficiency of off-the-shelf Si single-photon detectors; meanwhile, the heralded photon is in the telecom L-band where fiber losses are at a minimum. We observe spectral factorability of the SPDC source and consequently high purity (90%) of the produced heralded single photons by several different techniques. Because this source can also realize a high heralding efficiency (> 90%), it would be suitable for time-multiplexing techniques, enabling a pseudo-deterministic single-photon source, a critical resource for optical quantum information and communication technology.
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Kaneda
authors.forename: Karina
authors.initials: K
authors.lastname: Garay-Palmett
authors.forename: Alfred B
authors.initials: AB
authors.lastname: U'Ren
authors.forename: Paul G
authors.initials: PG
authors.lastname: Kwiat