Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Laguerre-Gauss beam generation in IR and UV by subwavelength
  surface-relief gratings   The angular momentum of light can be described by the states of spin angular
momentum, associated with polarization, and orbital angular momentum, related
to the helical structure of the wave front. Laguerre-Gaussian beams carry
orbital angular momentum and their generation can be done by using an optical
device known as q-plate. However, due to the usage of liquid crystals, these
components may be restricted to operate in specific wavelengths and low power
sources. Here we present the fabrication and characterization of q-plates made
without liquid crystals, using processes of e-beam lithography, atomic layer
depositions and dry etch techniques. We exploit the phenomenon of form
birefringence to give rise to the spin-to-orbital angular momentum conversion.
We demonstrate that these plates can generate beams with high quality for the
UV and IR range, allowing them to interact with high power laser sources or
inside laser cavities.

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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: math
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ph
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The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: solv-int
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom