Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Pulsed Sagnac source of polarization-entangled photon pairs in
  telecommunication band   We report a source of polarization-entangled photon pairs in the 1550-nm
telecommunication band, which is based on non-collinear spontaneous parametric
down-conversion in a periodically poled lithium niobate crystal pumped by
picosecond pulses. This source is realized utilizing a polarization-based
Sagnac interferometer employing a type-0 non-collinear quasi-phase-matching
configuration. Polarization entanglement is verified through measurement of the
polarization-correlation interference fringes with visibility >96% and by
testing the experimental violation of the Clauser-Horne-Shimony-Holt (CHSH)
form of Bell inequality. The CHSH-Bell parameter S is found to be 2.72 \pm
0.04, with 18 standard deviations from the statistical uncertainty.

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The categories of this paper are: q-bio
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The categories of this paper are: adap-org
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The categories of this paper are: q-alg
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The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: supr-con