Preparation and femtosecond non-linear optical properties of Ag/SiO2 composite thin films

Ag nanoparticles embedded in SiO2 thin films (Ag/SiO2 films) were prepared by a multitarget sputtering method. In the optical absorption spectra of the Ag/SiO2 films, the absorption peak due to the surface plasmon resonance (SPR) of Ag particle was clearly observed at the wavelength of 394-413 nm. The imaginary part of the third-order non-linear susceptibility, Im[chi((3))], of the Ag/SiO2 film was estimated to be -1.1 x 10(-8) esu measured by the femtosecond Z-scan technique near the SPR peak. The response time of the film measured from the decay of the differential transmission of the pump-probe experiment was 1.3 ps at the SPR peak.