Metal oxide doping effects on Raman spectra and third-order nonlinear susceptibilities of thallium–tellurite glasses

Third-order nonlinear optical susceptibilities (χ(3)) of thallium–tellurite (Tl2O–TeO2) glasses doped separately with various metal oxides (MOY/X; M = 22Ti(IV), 30Zn(II), 31Ga(III), 82Pb(II) and 83Bi(III)) were investigated using a femtosecond Z-scan technique. Surprisingly, the highest change in refractive index was obtained for M = Ti other than Pb and Bi, which was attributed to the formation of the TeO2/TiO2 glass structure without destruction of the initial three-dimensional network, accounting for a strong dielectric response intrinsic to pure TeO2 glass.