title: Photon correlation in single-photon frequency upconversion.
abstract: We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.
authors.affiliation: State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China, 200062.
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Gu
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.forename: Haifeng
authors.initials: H
authors.lastname: Pan
authors.forename: E
authors.initials: E
authors.lastname: Wu
authors.forename: Heping
authors.initials: H
authors.lastname: Zeng
mesh_terms: D003198:Computer Simulation; D007834:Lasers; D008027:Light; D008962:Models, Theoretical; D010783:Photometry / Q000379:methods*; D017785:Photons; D012542:Scattering, Radiation; D013223:Statistics as Topic