Sol-gel-derived binary silica glasses with high refractive index

Doped silica glasses, SiO 2 MO n/m (M = Ga, Gd, Nb, Sb, Sn, Ta, Ti and Zr), were prepared by the sol-gel method and evaluated. Refractive index and X-ray diffraction measurements showed that SiO 2 Sb 2 O 3 , SiO 2 Ta 2 O 5 , SiO 2 TiO 2 and SiO 2 ZrO 2 glasses are potentially suitable for optical components. Experimentally observed refractive indices are in good agreement with the calculated values using Appen's empirical law.