Structure and optical properties of TeO2-Nb2O5-BaCl2 glass

Abstract

Oxygen-chlorine tellurite glasses: (90-x)TeO2-10Nb2O5-xBaCl2 (x=10, 20, 30) are prepared using the conventional melting method. The influences of component on the density, structure, optical properties, refractive index and dispersion of the glasses are studied using density specific gravity balance, Raman spectroscopy, infrared-visible-UV spectrophotometer and Prism Coupler. The results show that the glass density first increases and then decreases with the increase of content of BaCl2. Furthermore, the structural units are converted from [TeO4] trigonal bipyramid into [TeO3] trigonal pyramid. Moreover, glass refractive index gradually decreases. In addition, new tellurite glass has high linear refractive index n (2.02259), nonlinear refractive index N2 (6.8× 10-12 esu) and third-order nonlinearpolarizability χ(3)(3.7× 10-13 esu). The new tellurite glass exhibits a high transmittance in the visible and infrared spectral region and possesses an cut-off edge in the near UV spectral region, and they each undergo an obvious blue shift with the increase of content of BaCl2. The direct and indirect transition optical band gaps of the samples are calculated according to the Tauc equation, and they increase with the content of BaCl2 increasing.