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Frontiers in Optics

Thick-crystal regime in photon pair sources

Brigitta Septriani, Kadir Durak, James A. Grieve, Alexander Ling

Published Jan 1, 2016• 0 citations
Publisher

Abstract

We present a thorough exploration of photon pair sources built around thick crystals, achieving concurrently high brightness and efficiency, despite pump beam walk-off. This surprising result is important when designing practical sources.
DOI
10.1364/fio.2016.ff5c.3

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We present comprehensive measurement data on the pump and collection beam parameters necessary to achieve high collection efficiency (89.0±1.7%89.0 \pm 1.7 \%89.0±1.7%) together with high brightness when a single βββ-Barium Borate crystal is operated in the thick-crystal regime and pumped with a narrow linewidth laser source. Spectral analysis of the collinear, non-degenerate photons suggest that the effective interaction length within the crystal is dominated by the collection beam mode and the use of longer crystals with increased spatial walk-off does not necessarily lead to a reduced collection efficiency. This result is an important consideration for optical designers who seek to develop practical photon pair sources.
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