Nonlinear absorptions in Au-nanoparticles-precipitated glasses induced by a femtosecond laser

We have investigated, by using Z-scan technique with ns pulses at 532nm, the nonlinear absorptions of Au-nanoparticles-precipitated glasses obtained by irradiation of focused femtosecond pulses with the help of heat treatment. We observed the saturable absorption behavior in Au-nanoparticles-precipitated glasses. We obtain, by fitting to the experimental results I in the light of the local field effect near the surface plasmon resonance, Imx(m)((3)) = 5.7 x 10(-7) esu for the imaginary parts of the third-order susceptibilities for Au nanoparticles. The nonlinear response of Au nanoparticles in the glass samples arises mainly from the hot electron contribution.