Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonlinear Optical Limiting with Hybrid Nanostructures of NiCo2O4 and
  Multiwall Carbon Nanotubes   Nonlinear optical (NLO) response in terms of reverse saturable absorption
(RSA) has been exploited extensively for optical limiting. Here, we
experimentally demonstrate that flower-like hybrid nanostructures of NiCo2O4
and Multiwall Carbon Nanotubes (NCO@MWCNT) exhibit a strong non-linearity in
their absorption, specifically an excited state absorption (ESA) induced RSA,
when exposed to nanosecond laser pulses. We obtain strong nonlinear absorption
coefficient (\b{eta}) and nonlinear refractive index (n2) in hybrid NCO@MWCNT,
the values that are 2-times and 2-orders of magnitude higher, respectively
compared to NCO or MWCNT alone. This offers straightforward application in
optical limiting with optical limiting (FOL) and optical onset (FON) threshold
ca. 2-10 times lower than benchmark NLO materials, e.g., graphene, family of
2-D transition metal dichalcogenides (TMDC) materials and recently established
NCO. Notably, for femtosecond pumping, NLO response of NCO@MWCNT is dominated
by saturable absorption (SA) with a week contribution from two photon
absorption (TPA), arising respectively from MWCNT and NCO. A remarkable sign
reversal along with a larger amplitude is obtained for n2 thanks to the charge
transfer from MWCNT to NCO.

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The categories of this paper are: hep-ex
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: bayes-an
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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: hep-th
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The categories of this paper are: astro-ph
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an