title: Widely tunable single photon source with high purity at telecom wavelength.
abstract: We theoretically and experimentally investigate the spectral tunability and purity of photon pairs generated from spontaneous parametric down conversion in periodically poled KTiOPO(4) crystal with group-velocity matching condition. The numerical simulation predicts that the spectral purity can be kept higher than 0.81 when the wavelength is tuned from 1460 nm to 1675 nm, which covers the S-, C-, L-, and U-band in telecommunication wavelengths. We also experimentally measured the joint spectral intensity at 1565 nm, 1584 nm and 1565 nm, yielding Schmidt numbers of 1.01, 1.02 and 1.04, respectively. Such a photon source is useful for quantum information and communication systems.
authors.affiliation: National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795, Japan. ruibo@nict.go.jp
authors.forename: Rui-Bo
authors.initials: RB
authors.lastname: Jin
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Shimizu
authors.forename: Kentaro
authors.initials: K
authors.lastname: Wakui
authors.forename: Hugo
authors.initials: H
authors.lastname: Benichi
authors.forename: Masahide
authors.initials: M
authors.lastname: Sasaki
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008029:Lighting / Q000295:instrumentation*; D017785:Photons; D013685:Telecommunications / Q000295:instrumentation*