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arXiv · 1007.3119

Three-color Sagnac source of polarization-entangled photon pairs

M. Hentschel·H. Hübel·A. Poppe·A. Zeilinger
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Abstract

We demonstrate a compact and stable source of polarization-entangled pairs of photons, one at 810 nm wavelength for high detection efficiency and the other at 1550 nm for long-distance fiber communication networks. Due to a novel Sagnac-based design of the interferometer no active stabilization is needed. Using only one 30 mm ppKTP bulk crystal the source produces photons with a spectral brightness of 1.13x10^6 pairs/s/mW/THz with an entanglement fidelity of 98.2%. Both photons are single-mode fiber coupled and ready to be used in quantum key distribution (QKD) or transmission of photonic quantum states over large distances.

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M. Hentschel, H. Hübel, A. Poppe, A. Zeilinger. 2010-07-19. Three-color Sagnac source of polarization-entangled photon pairs. https://doi.org/10.1364/oe.17.023153

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