Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Suppression of Brillouin oscillation in transparent free-standing
  diamond thin films in picosecond ultrasound   Brillouin oscillation appears in picosecond ultrasonics for a transparent
specimen because of backward light scattering by moving strain pulse. Its
amplitude is comparable with those of other responses, such as pulse-echo
signals and through-thickness resonance, obscuring these
non-Brillouin-oscillation responses. We here find that Brillouin oscillation
can be suppressed in a transparent free-standing film by coating both sides
with metallic thin film of appropriate thickness and that this peculiar
behavior is caused by strain pulses generated on both sides with a slight phase
difference. This phenomenon allowed us to fabricate a
Brillouin-oscillation-free diamond free-standing film, which showed high
capability for sensor applications.

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The categories of this paper are: patt-sol
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: ao-sci
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The categories of this paper are: econ
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The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: chem-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: chao-dyn
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The categories of this paper are: astro-ph
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The categories of this paper are: q-bio