Investigation of nonlinear optical properties of gold nanograins embedded in indium oxide films by reflection Z-scan using continuous laser

Abstract

Nanograins of gold-embedded in indium oxide thin films were fabricated by vacuum evaporation on silicon substrate. The gold concentrations were 3, 5, and 7 at. % as measured by x-ray fluorescence method. The x-ray diffraction results reveal that pure gold was crystallized into nanograins embedded in the indium oxide medium. The nonlinear optical properties of films on silicon substrate were investigated by reflection z-scan technique, using cw laser at 514 nm. Measurements of nonlinear refractive index and nonlinear absorption coefficient on these films are reported and the mechanism responsible for the process of optical nonlinearities is discussed.