Refractive Index Adjustment of SiO2 Gel Glass with Zirconium Oxychloride

ZrO2-SiO2 binary oxide gel glasses with various Zr contents were prepared by the sol–gel method with zirconium oxychloride and tetraethoxysilane as precursors. It is found that the refractive index of mixed oxide gel glass is linear with the Zr content and suitable heat treatment will give rise to an increase in the refractive index. By employing FTIR techniques, a new Zr—O—Si bond has been investigated with part of the zirconium ions being incorporated into the silica network. The capability to tune the refractive index for the blend sample with Zr ions and to obtain a stable refractive index at relative low treatment temperature suggests that the gel glass is potential matrix for doping with near IR fluorescence organic dyes and make them promising materials for active optical waveguides.