Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two-color discrete localized modes and resonant scattering in arrays of
  nonlinear quadratic optical waveguides   We analyze the properties and stability of two-color discrete localized modes
in arrays of channel waveguides where tunable quadratic nonlinearity is
introduced as a nonlinear defect by periodic poling of a single waveguide in
the array. We show that, depending on the value of the phase mismatch and the
input power, such two-color defect modes can be realized in three different
localized states. We also study resonant light scattering in the arrays with
the defect waveguide.

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The categories of this paper are: astro-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: eess
34
The categories of this paper are: chem-ph
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The categories of this paper are: econ
20
The categories of this paper are: acc-phys
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
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The categories of this paper are: q-bio
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The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat