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International Conference on Quantum Information

Investigating the entanglement structure of down-converted photon pairs

Filippo M. Miatto, Alison M. Yao, Stephen Mark Barnett, Miles J. Padgett, Barry Jack

Published Jan 1, 2011• 1 citation
Publisher

Abstract

We investigate the entanglement of photons produced by spontaneous parametric down-conversion. We analyse the down-converted state for any pump beam and for any detection modes in the complete Laguerre-Gauss basis.
DOI
10.1364/icqi.2011.qtuf6

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Abstract In this work, we investigate the orbital angular momentum (OAM) spectrum of photons generated via spontaneous parametric down-conversion (SPDC) and study how shaping the transverse profile of the pump beam influences the resulting spectrum. Using a perfect optical vortex (POV) mode as the pump, we show that the OAM spectrum narrows significantly, leading to purer OAM states. We further examine the entanglement between the down-converted photons in the OAM basis, finding that Laguerre–Gaussian (LG) pumped photons exhibit increased higher-dimensional entanglement at the expense of mode purity.
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