title: Ultrafast switching time and third order nonlinear coefficients of microwave treated single walled carbon nanotube suspensions.
abstract: Microwave treated water soluble and amide functionalized single walled carbon nanotubes have been investigated using femtosecond degenerate pump-probe and nonlinear transmission experiments. The time resolved differential transmission using 75 femtosecond pulse with the central wavelength of 790 nm shows a bi-exponential ultrafast photo-bleaching with time constants of 160 fs (130 fs) and 920 fs (300 fs) for water soluble (amide functionalized) nanotubes. Open and closed aperture z-scans show saturation absorption and positive (negative) nonlinear refraction for water soluble (amide functionalized) nanotubes. Two photon absorption coefficient, beta0 approximately 250 cm/GW (650 cm/GW) and nonlinear index, gamma approximately 15 cm2/pW (-30 cm2/pW) are obtained from the theoretical fit in the saturation limit to the data for two types of nanotubes.
authors.affiliation: Department of Physics and Centre for Ultrafast Laser Applications, Indian Institute of Science, Bangalore 560012, India.
authors.forename: N
authors.initials: N
authors.lastname: Kamaraju
authors.forename: Sunil
authors.initials: S
authors.lastname: Kumar
authors.forename: B
authors.initials: B
authors.lastname: Karthikeyan
authors.forename: Bhalchandra
authors.initials: B
authors.lastname: Kakade
authors.forename: Vijayamohanan K
authors.initials: VK
authors.lastname: Pillai
authors.forename: A K
authors.initials: AK
authors.lastname: Sood