Abstract
SiO2 glass for optical fiber is prepared from colloidal sol-gel process. The fumed silica is used for the preparation. The silica is dispersed in water containing with TMAH, surface-active agent and glycerin, and the ratio of the silica to water is 60-70 weight%. The sol solution is gelled immediately after addition of methyl formate, when the initial pH value of the sol is over 11. The gel is dried, refined in SOCl2 and sintered at 1500°C in air or He atmosphere. In the case of the sintering process in He atmosphere, the silica sample hardly crystallizes.
