title: Efficient frequency downconversion at the single photon level from the red spectral range to the telecommunications C-band.
abstract: We report on single photon frequency downconversion from the red part of the spectrum (738 nm) to the telecommunications C-band. By mixing attenuated laser pulses with an average photon number per pulse < 1 with a strong continuous light field at 1403 nm in a periodically poled Zn:LiNbO3 ridge waveguide an internal conversion efficiency of ∼ 73% is achieved. We further investigate the noise properties of the process by measuring the output spectrum. Our results indicate that by narrow spectral filtering a quantum interface should be feasible which bridges the wavelength gap between quantum emitters like color centers in diamond emitting in the red part of the spectrum and low-loss fiber-optic telecommunications wavelengths.
authors.affiliation: Universität des Saarlandes, Fachrichtung 7.2 (Experimentalphysik), Campus E2.6, 66123 Saarbrücken, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Zaske
authors.forename: Andreas
authors.initials: A
authors.lastname: Lenhard
authors.forename: Christoph
authors.initials: C
authors.lastname: Becher
mesh_terms: D003116:Color; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation* / Q000379:methods*; D007834:Lasers; D009556:Niobium / Q000737:chemistry; D017711:Nonlinear Dynamics; D010087:Oxides / Q000737:chemistry; D017785:Photons; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman / Q000379:methods; D013685:Telecommunications / Q000295:instrumentation*; D015032:Zinc / Q000737:chemistry
chemical_list: D010087:Oxides; D009556:Niobium; C091692:lithium niobate; D015032:Zinc