Coherent phonon generation in semiconducting single-walled carbon nanotubes using a few-cycle pulse laser

Coherent phonon dynamics in single-walled carbon nanotubes with several chiralities is investigated by 7.1-fs pump–probe experiments. Vibrational wave-packets corresponding to the radial breathing mode (RBM) and G mode can be detected for four chiral systems, (6,4), (6,5), (7,5) and (8,3). Coherent phonon generation of RBMs is in-depth studied by analyzing the probe photon energy dependent amplitude profiles, which indicates that the real and imaginary parts of the third-order susceptibility can both contribute to the modulation of the probed difference absorbance.