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arXiv · 0807.1573

Joint Temporal Density Measurements for Two-Photon State Characterization

Onur Kuzucu·Franco N. C. Wong·Sunao Kurimura·Sergey Tovstonog
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Abstract

We demonstrate a new technique for characterizing two-photon quantum states based on joint temporal correlation measurements using time resolved single photon detection by femtosecond upconversion. We measure for the first time the joint temporal density of a two-photon entangled state, showing clearly the time anti-correlation of the coincident-frequency entangled photon pair generated by ultrafast spontaneous parametric down-conversion under extended phase-matching conditions. The new technique enables us to manipulate the frequency entanglement by varying the down-conversion pump bandwidth to produce a nearly unentangled two-photon state that is expected to yield a heralded single-photon state with a purity of 0.88. The time-domain correlation technique complements existing frequency-domain measurement methods for a more complete characterization of photonic entanglement in quantum information processing.

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Onur Kuzucu, Franco N. C. Wong, Sunao Kurimura, Sergey Tovstonog. 2008-07-10. Joint Temporal Density Measurements for Two-Photon State Characterization. https://doi.org/10.1103/physrevlett.101.153602

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