Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evolution and spatial distribution of Brillouin backscattering
  associated to hybrid acoustic modes in sub-wavelength silica microfibers   The spectral evolution and spatial distribution of backscattered Brillouin
signals is experimentally investigated in sub-wavelength silica microfibers.
The Brillouin spectrum evolution reveals the different dynamics of the various
peaks, offering evidence of backscattering signals induced by acoustic waves
with phase velocity greater than that of the longitudinal wave. The spatial
distribution is found to have significant influence on the response of
Brillouin scattering under tensile load, with hybrid acoustic modes providing a
smaller response under axial strain. This insight into interactions between
optical and hybrid acoustic modes at sub-wavelength confinements could help
understand ultrasonic waves in tapered waveguides, and have potential
applications in optical sensing and detection.

35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
2
The categories of this paper are: math
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin