title: Large optical nonlinearity of semiconducting single-walled carbon nanotubes under resonant excitations.
abstract: We measured third-order nonlinear susceptibility (chi(3)) spectra in semiconducting single-walled carbon nanotubes (SWNTs) by the Z-scan method. |Imchi(3)| is remarkably enhanced under resonant excitation to the lowest interband transition, reaching 4.2 x 10(-6) esu and 1.5 x 10(-7) esu in SWNTs grown by the laser ablation and HiPco methods, respectively. A comparison of the transient absorption changes evaluated by degenerate and nondegenerate pump-probe measurements suggests that the resonant enhancement of |Imchi(3)| is dominated by a coherent process rather than by saturation of absorption.
authors.affiliation: Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Maeda
authors.forename: S
authors.initials: S
authors.lastname: Matsumoto
authors.forename: H
authors.initials: H
authors.lastname: Kishida
authors.forename: T
authors.initials: T
authors.lastname: Takenobu
authors.forename: Y
authors.initials: Y
authors.lastname: Iwasa
authors.forename: M
authors.initials: M
authors.lastname: Shiraishi
authors.forename: M
authors.initials: M
authors.lastname: Ata
authors.forename: H
authors.initials: H
authors.lastname: Okamoto