Temporal Quantum-State Tomography of Narrowband Biphotons

ORAL

Abstract

We demonstrate a technique of quantum-state tomography for measuring the complex temporal wave function of narrowband biphotons with polarization-dependent and time-resolved two-photon interference. While the amplitude function of the biphoton waveform is directly related to the second-order correlation function which is determined by the two-photon coincidence measurement, the phase function is retrieved from six sets of time-resolved two-photon interference measurements projected onto different polarization subspaces. We apply this technique to experimentally reconstruct the temporal quantum states of the narrow-band biphotons generated from the spontaneous four-wave mixing in cold atoms. As compared with the homodyne detection, our method doesn't require any external phase reference.

*The work was supported by the Hong Kong Research Grants Council (Project No. 601113).

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Authors

  • Xianxin Guo

    • the Hong Kong University of Science and Technology
    • Hong Kong University of Science and Technology

  • Peng Chen

    • the Hong Kong University of Science and Technology
    • Hong Kong University of Science and Technology

  • Chi Shu

    • the Hong Kong University of Science and Technology

  • M.M.T. Loy

    • the Hong Kong University of Science and Technology
    • Department of Physics, Hong Kong University of Science and Technology
    • Hong Kong University of Science and Technology

  • Shengwang Du

    • the Hong Kong University of Science and Technology
    • Department of Physics, Hong Kong University of Science and Technology
    • Hong Kong University of Science and Technology