Glass used in the production of optical parts and materials for optical transmission media such as optical waveguides comprises silicon dioxide containing hydroxide groups, chlorine and fluorine

摘要

Glass comprises silicon dioxide containing not more than 10 ppm hydroxide groups, not more than 10 ppm chlorine and not less than 1000 ppm fluorine. The gas has a concentration ratio of F/Cl of 100 or more. Preferred Features: The silicon dioxide contains not more than 10 ppm hydroxide groups, not more than 10 ppm chlorine and not less than 1000 ppm F with a gas concentration ratio of F/Cl of 1000 or more or not more than 10 ppm hydroxide groups, not more than 10 ppm chlorine and not less than 1000 ppm F with a gas concentration ratio of F/Cl of 10000 or more.