Nonlinear Optical Response in Single-Walled Carbon Nanotubes under Resonant Excitation Conditions

Abstract

Abstract. Third-order nonlinear optical responses in single walled carbon nanotubes have been investigated by means of pump-probe spectroscopy with various excitation conditions. In the excitation spectra of nonlinear susceptibilities probed at the E 22 transition energy of the (8,4) tube, an additional peak is observed at ~0.2 eV above the E 22 transition energy. It is found that the phonon-assisted transition is involved in the third-order nonlinear optical processes.