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Physical Review A

Conversion of transverse momentum correlation of photon pairs into polarization entanglement by using wavefront-splitting interference

Csaba Tamás Holló, Tamás Sarkadi, Máté Galambos, Attila Barócsi, Pál Koppa, Veronika Hanyecz, Gábor Erdei

Published Dec 15, 2022• 2 citations
Publisher

Abstract

The transverse momentum correlation of photon pairs generated by noncollinear spontaneous parametric down-conversion with type-I phase matching is transformed into polarization entanglement. A robust wavefront-splitting interferometer scheme is used, due to which the phase of the entangled state does not require active stabilization. Frequency-degenerate signal and idler photons are separated and coupled into single-mode optical fibers. The concept is demonstrated in a compact and modular setup. A straightforward alignment process for producing any of the Bell states is presented. The entangled source has an output photon flux of $8.33\ifmmode\pm\else\textpm\fi{}1.27$ kcps/mW normalized to pump power (150 mW), and $17\ifmmode\pm\else\textpm\fi{}3%$ heralding ratio. The measured state fidelity with respect to the negative anticorrelated Bell state is $0.951\ifmmode\pm\else\textpm\fi{}0.004$.

DOI
10.1103/physreva.106.063710

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