Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Large nonlinear absorption and refraction coefficients of carbon
  nanotubes estimated from femtosecond Z-scan measurements   Nonlinear transmission of 80 and 140 femtosecond pulsed light with $0.79 \mu
m$ wavelength through single walled carbon nanotubes suspended in water
containing sodium dodecyl sulphate is studied. Pulse-width independent
saturation absorption and negative cubic nonlinearity are observed,
respectively, in open and closed aperture Z-scan experiments. The theoretical
expressions derived to analyze the z-dependent transmission in the saturable
limit require two photon absorption coefficient $\beta_0\sim$ $1.4 cm/MW$ and a
nonlinear index $\gamma \sim -5.5 \times10^{-11} cm^2/W$ to fit the data.

35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys