Sodium magnesium silicate oxyfluoride glass with low Rayleigh scattering

Oxyfluoride glass in the system Na-Mg-Si-O-F, which exhibits lower Rayleigh scattering than silica glass, has been developed. The glass forming region is extended for an F content of up to 30% of the anions. Scattering measurements for (1-x) (Na2O . 2SiO(2))-xMgF(2) glasses revealed that the scattering intensity decreases to 70% of the intensity of silica glass for a MgF2 content of 5 mol%. The factors affecting scattering were evaluated based on glass properties such as refractive index dispersion parameters and glass transition temperature. The results suggest that the scattering in this glass is dominated by the density fluctuation.