Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High power high repetition rate supercontinuum generation in
  graded-index multimode fibers   Graded-index multimode fibers can handle high average powers and feature
unique nonlinear dynamics due to spatio-temporal evolution of the light inside.
We report on generation of octave-spanning spectrally flat supercontinua in
graded-index multimode fibers using a compact, ytterbium-doped all-fiber laser
system. Supercontinua with output powers as high as $\sim$4 W and 2 MHz
repetition rate obtained with more than 1 $\mu$m spectral bandwidth. Evolution
of supercontinuum is investigated by studying the effect of launch power,
repetition rate, fiber length and core size. Numerical simulations are
performed to investigate underlying nonlinear dynamics in details and
calculated results are well-aligned with experimental spectra. To the best of
our knowledge, this the highest average power and repetition supercontinuum
source ever reported in a standard graded-index multimode silica fiber

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The categories of this paper are: dg-ga
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The categories of this paper are: q-alg
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
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The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
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The categories of this paper are: econ