High-order nonlinearities of aqueous colloids containing silver nanoparticles

The optical nonlinearity of an aqueous colloid containing silver nanoparticles (NPs) was investigated using the Z-scan technique. Values for the third-, fifth-, seventh-, and ninth-order susceptibilities were obtained, and their dependence with the volume fraction occupied by the NPs was determined. The experiments were performed with intensities between 0.1 and 1.5 GW/cm2 using a laser at 532 nm that delivers single 80 ps pulses at a low repetition rate.