Free induction decay of the coherent electronic transition and coherent phonon oscillations of the radial breathing mode in single-walled carbon nanotubes are simultaneously observed via direct resonant excitation of the lowest E(11) optical transition in the near-infrared region from 0.939 to 1.1 eV. We show that coherent electronic oscillations corresponding to the detuning of the probe energy from resonance can be exploited for the chirality assignment of carbon nanotubes, together with the robust assignment of the coherent lattice vibrations resonantly excited by femtosecond pulses. Excitation spectra show a large number of pronounced peaks that map out chirality distributions in great detail.
© 2012 American Chemical Society