Role of pump coherence in two-photon interferometry

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Citation of Original Publication

J. Liang, S. M. Hendrickson, and T. B. Pittman, Role of pump coherence in two-photon interferometry, Phys. Rev. A 83, 033812 (2011), DOI:


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©2011 American Physical Society



We use a parametric down-conversion source pumped by a short-coherence-length continuous-wave (CW) diode laser to perform two-photon interferometry in an intermediate regime between the more familiar Franson-type experiments with a long-coherence-length pump laser, and the short pulsed pump “time-bin” experiments pioneered by Gisin’s group. The use of a time-bin-like Mach-Zehnder interferometer in the CW pumping beam induces coherence between certain two-photon amplitudes, while the CW nature of the experiment prevents the elimination of remaining incoherent ones. The experimental results highlight the role of pump coherence in two-photon interferometry.