Abstract
Densification of glass is an interesting method to control optical properties of glass, such as refractive index, wavelength dispersion of refractive index, optical durability and so on, without changing its chemical composition. In this paper, densification of silica glass by means of hot isostatic pressing (HIP) and structural relaxation of the densified glass at elevated temperatures have been investigated. Two types of synthetic silica glass which have high and low OH contents were used in this experiment. The density of glass increased by about 1% after HIP treatment of 2000kgf/cm2, 1200°C, 2hrs. The refractive index (n) increased with increasing density.
The wavelength dispersion of index (dn/dλ) also increased by the densification. X-ray induced absorptions at 4.8eV and 5.8eV were suppressed by the densification. The structure of the high- and low-OH glasses was stable up to about 600 and 800°C, respectively. These results suggest that the densified silica glass can be widely applied to optical use.
