Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Picosecond opto-acoustic interferometry and polarimetry in high-index
  GaAs   By means of a metal opto-acoustic transducer we generate quasi-longitudinal
and quasi-transverse picosecond strain pulses in a (311)-GaAs substrate and
monitor their propagation by picosecond acoustic interferometry. By probing at
the sample side opposite to the transducer the signals related to the
compressive and shear strain pulses can be separated in time. In addition to
conventional monitoring of the reflected probe light intensity we monitor also
the polarization rotation of the optical probe beam. This polarimetric
technique results in improved sensitivity of detection and provides
comprehensive information about the elasto-optical anisotropy. The experimental
observations are in a good agreement with a theoretical analysis.

15
The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: stat
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The categories of this paper are: econ
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: eess
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th