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Two-photon coincident-frequency-entanglement via extended phase matching

Onur Kuzucu·Marco Fiorentino·Marius A. Albota·Franco N. C. Wong·Franz X. Kaertner
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Abstract

We demonstrate a new class of frequency-entangled states generated via spontaneous parametric down-conversion under extended phase matching conditions. Biphoton entanglement with coincident signal and idler frequencies is observed over a broad bandwidth in periodically poled KTiOPO$_4$. We demonstrate high visibility in Hong-Ou-Mandel interferometric measurements under pulsed pumping without spectral filtering, which indicates excellent frequency indistinguishability between the down-converted photons. The coincident-frequency entanglement source is useful for quantum information processing and quantum measurement applications.

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Onur Kuzucu, Marco Fiorentino, Marius A. Albota, Franco N. C. Wong, Franz X. Kaertner. 2005-03-01. Two-photon coincident-frequency-entanglement via extended phase matching. https://doi.org/10.1103/physrevlett.94.083601

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