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Frontiers in Optics

Bright Entangled Photon Source Optimized for Single Mode Emission and Minimum Spectral Entanglement

Philip G. Evans, Ryan S. Bennink, Warren P. Grice, Travis S. Humble, J. Schaake

Published Jan 1, 2009• 0 citations
Publisher

Abstract

We describe an entangled photon source based on collinear down-conversion in periodically-poled KTP at 1552 nm. The pump bandwidth, crystal length, and pump spatial mode are chosen so as to minimize spectral and spatial entanglement.
DOI
10.1364/fio.2009.jma4

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We present results of a bright polarization-entangled photon source operating at 1552 nm via type-II collinear degenerate spontaneous parametric down-conversion in a periodically poled potassium titanyl phosphate crystal. We report a conservative inferred pair generation rate of 123,000 pairs/s/mW into collection modes. Minimization of spectral and spatial entanglement was achieved by group velocity matching the pump, signal, and idler modes and through properly focusing the pump beam. By utilizing a pair of calcite beam displacers, we are able to overlap photons from adjacent down-conversion processes to obtain polarization-entanglement visibility of 94.7+/-1.1% with accidentals subtracted.
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