Optical characterization of xTiO2–(60 − x)SiO2–40Na2O glasses: I. Linear and nonlinear dispersion properties

Different xTiO2–(60 − x)SiO2–40Na2O (5 ≤ x ≤ 20 wt.%) glasses are prepared in the form of plane parallel slabs. The optical constants of these optical glasses are determined over a wide spectral range, 0.2–3 μm, providing the complex dielectric constant to be calculated. The different dispersion parameters of the studied compositions are determined as well. Higher values for the refractive index and dispersion are recorded due to the high polarizability of Ti and the low preference of 4-coordination for titanium. The wavelength for zero material dispersion is evaluated. The second-order index of refraction and the third-order nonlinear optical susceptibility are computed from the measured linear refractive index data. These nonlinear properties of the present glass show one order of magnitude enhancement over some TiO2 silicate glasses. The measured mid-IR-spectra of the different glasses are carried out to investigate the structure of the present glasses. It has been found that, the addition of titanium (i.e., highly polarizable element) not only acts as glass modifier but also behaves as intermediate and Ti4+ exalts more the measured glass parameters.