Structural investigation of new tellurite glasses belonging to the TeO2-NbO2.5-WO3 system, and a study of their linear and nonlinear optical properties

Abstract The glass-forming domain, density, thermal, structural and optical properties of new glasses within the TeO 2 -NbO 2.5 -WO 3 system have been investigated. By means of Raman spectroscopy, a thorough structural analysis of these glasses has been undertaken on the basis of a full-scale spectral decomposition process. The optical transmission window, refractive index dispersion and third-order nonlinear susceptibilities χ (3) were measured by UV–Vis-NIR spectroscopy, spectroscopic ellipsometry and Z -scan method respectively. Consistent correlations are successfully established between the measured structural, linear and nonlinear optical properties. In general, the structural features of the glass network are found to evolve mildly upon adding NbO 2.5 or WO 3 . Nonetheless, a weak structural depolymerization of the Te O Te bond network as a result of adding NbO 2.5 is evidenced and discussed in detail. Upon continuous addition of NbO 2.5 and/or WO 3 , the glass network becomes progressively richer in NbO 2.5 -rich and/or WO 3 -rich regions before the crystallization of Nb 6 TeO 17 (NbO 2.5 :TeO 2 ratio of 6:1) and WO 2.83 compounds respectively. The studied glasses exhibit high linear refractive indices with an average of ~2.13 and very high third-order nonlinear susceptibilities χ (3) with an average of 5.48 *10 −13  esu (~37 times higher than that of SiO 2 glass).