Nonlinear light scattering in a carbon nanotube suspension

Nonlinear scattering of 1064-nm laser light in an aqueous suspension of purified carbon nanotubes has been studied in relation to their optical power limiting behaviour using z-scan measurements to simultaneously determine the energy and shape of the transmitted and 90° scattered pulses. The results indicate that the reduction in transmitted laser pulse energy with increasing incident power density is mainly due to the associated increase in scattered pulse energy. The shape, duration and time shift of the transmitted and 90° scattered pulses are intricate functions of incident power density. The data are interpreted in terms of thermally induced nonlinear and Rayleigh scattering processes at high and low incident power densities, respectively.