Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Harmonic Generation in Metallic, GaAs-Filled Nanocavities in the
  Enhanced Transmission Regime at Visible and UV Wavelengths   We have conducted a theoretical study of harmonic generation from a silver
grating having slits filled with GaAs. By working in the enhanced transmission
regime, and by exploiting phase-locking between the pump and its harmonics, we
guarantee strong field localization and enhanced harmonic generation under
conditions of high absorption at visible and UV wavelengths. Silver is treated
using the hydrodynamic model, which includes Coulomb and Lorentz forces,
convection, electron gas pressure, plus bulk X(3) contributions. For GaAs we
use nonlinear Lorentz oscillators, with characteristic X(2) and X(3) and
nonlinear sources that arise from symmetry breaking and Lorentz forces. We find
that: (i) electron pressure in the metal contributes to linear and nonlinear
processes by shifting/reshaping the band structure; (ii) TEand TM-polarized
harmonics can be generated efficiently; (iii) the X(2) tensor of GaAs couples
TE- and TM-polarized harmonics that create phase-locked pump photons having
polarization orthogonal compared to incident pump photons; (iv) Fabry-Perot
resonances yield more efficient harmonic generation compared to plasmonic
transmission peaks, where most of the light propagates along external metal
surfaces with little penetration inside its volume. We predict conversion
efficiencies that range from 10-6 for second harmonic generation to 10-3 for
the third harmonic signal, when pump power is 2GW/cm2.

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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: stat
7
The categories of this paper are: hep-th
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio
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The categories of this paper are: ao-sci
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc