Glass formation and mid-infrared optical nonlinearities of chalcogenide glasses in germanium-tin-sulfur ternary system
Résumé
The glass forming region of chalcogenide glasses in a germanium-tin-sulfur (Ge-Sn-S) ternary system is depicted. Three series of Ge-Sn-S glasses in different compositions are selected and synthesized in order to investigate the dependence of structural, optical and third-order nonlinear properties on chemical composition. Spectroscopy analyses demonstrate that Ge and Sn have similar structural behavior in the glass network, while the introduction of Sn decreases the optical bandgap energy and improves the infrared transmittance of the glasses. Third-order nonlinear properties of the glasses are investigated by the Z-scan technique at a mid-infrared wavelength of 3.3 mu m. The experimental results demonstrate that the nonlinear absorption at the mid-infrared wavelength is absent due to the large optical bandgap energy of the glasses, while the nonlinear refractive behavior is evident and can be improved by reducing number of [GeS4] tetrahedrons in the glass network. (C) 2016 Optical Society of America