Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Study of Propagating Modes and Reflectivity in Bragg Filters with
  AlxGa1-xN/GaN Material Composition   In this paper, forward and backward propagating waves and reflectivity in an
optical waveguide structure namely the fiber Bragg reflector also considered as
a one dimensional photonic crystal, are analytically computed using coupled
mode theory for different grating lengths and coupling conditions.
AlxGa1-xN/GaN material composition is considered as unit block of the periodic
organization, and refractive index of AlxGa1-xN is taken to be dependent on
material composition, bandgap and operating wavelength following Adachis'
model. The structure being considered is the Bragg grating where increase in
grating length enhances the reflection of electromagnetic wave, and strong
coupling provides larger bandgap spectral width. Input wavelength is made
different from Bragg wavelength to study the characteristics of propagating
waves. A suitable combination of grating length and coupling coefficient is
helpful in designing the photonic bandgap at 1550 nm wavelength. These
characteristic curves can be utilized to study how waves propagate through the
optical waveguides which have a special place in optical communications

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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: cmp-lg
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The categories of this paper are: stat
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: hep-lat