Investigations of structure and nonlinear optical properties of gold doped germanium–gallium–sulfur chalcogenide glasses

Abstract Chalcogenide glass in molar composition of Ga 10 Ge 25 S 65 (GGS) and same glasses doped with various amount of gold were prepared. Both density and refractive index of the glasses increased with increase of gold content. Optical band gap ( E opg ) of the GGS glasses was obtained by Tauc and Menth's method, and the E opg value decreased with increase of gold content. Analysis of Raman spectra informed that the main frame of the glasses was constructed by [GeS 4 ] tetrahedra and no characteristic band belonging to gold was observed, indicating that gold behaved as a glass modifier for the GGS glasses. To investigate the influence the gold has on third-order optical nonlinearities of the GGS glasses, femtosecond Z-scan measurements were conducted at the wavelength of 800 nm. The results showed that the performance of third-order optical nonlinearities of the GGS glasses was improved by introduction of gold.