# Large nonlinear absorption and refraction coefficients of carbon nanotubes estimated from femtosecond z-scan measurements

Kamaraju, N and Kumar, Sunil and Sood, AK and Guha, Shekhar and Krishnamurthy, Srinivasan and Rao, CNR (2007) Large nonlinear absorption and refraction coefficients of carbon nanotubes estimated from femtosecond z-scan measurements. In: Applied Physics Letters, 91 (25). 251103-1-251103-3.

 PDF cvips.pdf Restricted to Registered users only Download (194Kb) | Request a copy

## Abstract

Nonlinear transmission of 80 and 140 fs pulsed light with $0.79 \mu m$ wavelength through single walled carbon nanotubes suspended in water containing sodium dodecyl sulfate 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 $\gamma \sim -5.5 \times 10^{-11} cm^2/W$ to fit the data.

Item Type: Journal Article Copyright of this article belongs to American Institute of Physics. Division of Physical & Mathematical Sciences > Physics 08 Aug 2008 19 Sep 2010 04:48 http://eprints.iisc.ernet.in/id/eprint/15508