Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Large-area fabrication of low- and high-spatial-frequency laser-induced
  periodic surface structures on carbon fibers   The formation and properties of laser-induced periodic surface structures
(LIPSS) were investigated on carbon fibers under irradiation of fs-laser pulses
characterized by a pulse duration $\tau$ = 300 fs and a laser wavelength
$\lambda$ = 1025 nm. The LIPSS were fabricated in an air environment at normal
incidence with different values of the laser peak fluence and number of pulses
per spot. The morphology of the generated structures was characterized by using
scanning electron microscopy, atomic force microscopy and Fast-Fourier
transform analyses. Moreover, the material structure and the surface chemistry
of the carbon fibers before and after laser irradiation was analyzed by micro
Raman spectroscopy and X-ray photoelectron spectroscopy. Large areas in the
cm$^{2}$ range of carbon fiber arrangements were successfully processed with
homogenously distributed high- and low-spatial frequency LIPSS. Beyond those
distinct nanostructures, hybrid structures were realized for the very first
time by a superposition of both types of LIPSS in a two-step process. The
findings facilitate the fabrication of tailored LIPSS-based surface structures
on carbon fibers that could be of particular interest for e.g. fiber reinforced
polymers and concretes.

17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom