Structural and Nonlinear Optical Characterizations of Tellurium Oxide-Based Glasses: TeO2–BaO–TiO2

The structure of the pseudo ternary TeO2–TiO2–BaO glasses was investigated by Raman and infrared spectroscopies. In the TeO2–BaO system, glasses with low BaO content have a continuous network constructed by sharing corners of TeO4trigonal bipyramids and TeO3+1polyhedra having nonbridging oxygen atoms. In glasses containing 40% mol BaO, isolated structural units such as TeO3are formed. However, TiO2insertion can inhibit this structural change and favor a continuous network. We discuss the characterization of nonlinear optical process in these materials using Z scan technique. The highest nonlinear absorption values are obtained for titanium tellurite glasses emphasising the particularly significant role of the structural units in the optical response.