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Fiber-Optic Sources of Quantum Entanglement

P. Kumar·X. Li·M. Fiorentino·P. L. Voss·J. E. Sharping·G. A. Barbosa
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Abstract

We present a fiber-based source of polarization-entangled photon pairs that is well suited for quantum communication applications in the 1.5$μ$m band of standard telecommunication fiber. Quantum-correlated signal and idler photon pairs are produced when a nonlinear-fiber Sagnac interferometer is pumped in the anomalous-dispersion region of the fiber. Recently, we have demonstrated nonclassical properties of such photon pairs by using Geiger-mode InGaAs/InP avalanche photodiodes. Polarization entanglement in the photon pairs can be created by pumping the Sagnac interferometer with two orthogonally polarized pulses. In this case the parametrically scattered signal-idler photons yield biphoton interference with $>$90% visibility in coincidence detection, while no interference is observed in direct detection of either the signal or the idler photons.

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P. Kumar, X. Li, M. Fiorentino, P. L. Voss, J. E. Sharping, G. A. Barbosa. 2002-09-20. Fiber-Optic Sources of Quantum Entanglement. https://arxiv.org/abs/quant-ph/0209112

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