Properties of Structure and Mid-infrared Transmission in TeO_2-ZnCl_2-BaO-NaF Glass System

Oxyhalide tellurite glasses: (80-x)TeO2-15ZnCl2-xBaO-5NaF(x=30,20,10,0mol%) were prepared. The mechanical strength performance, thermal properties, Raman spectra, UV absorption spectra and Infrared transmission spectra of the samples were investigated. The effects of composition content change on the structure and infrared transmission properties of glasses were investigated by means of Raman scattering. The results show that the transmission in mid-infrared region significantly increases and the IR cut-off shifts towards longer wavelength with increasing BaO, the mechanism was also discussed. The addition of halide to the glasses and the treatment with pure O2 during melting are useful for the decrease of OH-1 absorption bands, meanwhile the infrared transmittance is increased. The presented oxyhalide tellurite glass is a kind of optical material with high infrared transmission. It exhibits a high transmittance (≥80%) in the mid-infrared regions and possesses an infrared cut-off edge up to 6.5μm.