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Quantum Electronics and Laser Science Conference

Joint spectrum mapping of polarization entanglement in parametric down-conversion

Hou Shun Poh, Chune Yang Lum, I. Marcikic, Antı́a Lamas-Linares, Christian Kurtsiefer

Published May 1, 2007• 0 citations
Publisher

Abstract

Spectral mapping of the polarization correlations of photon pairs from down-conversion in femtosecond regime reveals an imbalance between contributions from the two possible decay paths as the cause of low entanglement quality.
DOI
10.1109/qels.2007.4431719

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Generation of polarization-entangled photon pairs with a precise timing through down-conversion of femtosecond pulses is often faced with a degraded polarization entanglement quality. In a previous experiment, we have shown that this degradation is induced by spectral distinguishability between the two decay paths, in accordance with theoretical predictions. Here, we present an experimental study of the spectral compensation scheme proposed and first implemented by Kim and Grice [J. Mod. Opt. 49, 2309 (2002)]. By measuring the joint spectral properties of the polarization correlations of the photon pairs, we show that the spectral distinguishability between the down-converted components is eliminated. This scheme results in a polarization visibility of $97.9\ifmmode\pm\else\textpm\fi{}0.5%$ without any spectral filtering.