Optical properties of Au nanoparticle dispersed (Ba,Sr)TiO3 thin films

An nanoparticles dispersed (Ba,Sr)TiO3 -thin films were fabricated using alternating sputtering method. With the nominal thickness of An layer of 1 nm, the spherical An particles of 3.83 nm size were obtained showing the spatial distribution referred to a Maxell-Gamett type effective medium geometry. The film shows the characteristic surface plasmon resonance absorption band at 571 nm. Based on the effective medium theory, the linear optical functions of the films were characterized. The third-order optical nonlinearity was analyzed by a single beam Z-scan technique with a picosecond pulse laser. The real and imaginary parts of third-order susceptibility can be resolved at several wavelengths around the SPR by virtue of wavelength tunable optical parametric generator. The maximum absolute value of third-order susceptibility as large as 3.847 x 10(-8) esu were obtained at the SPR frequency.