Nonlinear optical properties in three novel nanocomposites with gold nanoparticles

Nonlinear optical properties of three novel nanocomposites with zerovalent noble metal gold nanoparticles were investigated by using Z-scan technique. Optical limiting effects has been measured with 8 ns pulses at 532 nm. The cross-sections of nonlinear absorption were obtained by the simulation with a simplified model in which the effective excited-state absorptions of three ligands in nanocomposites were considered. The nonlinear refractive indices were calculated from the data of Z-scan measurement. The experimental results were found to be significantly different in these nanocomposites. Optical nonlinearities in these nanocomposites can be attributed to the strong excited-state absorptions of the ligands and the surface plasmon resonance of gold nanoparticles.