Method for producing silica glass for use with light in a vacuum ultraviolet wavelength range

A method for producing a synthetic silica glass for use with light in a vacuum ultraviolet wavelength range, comprising the steps of:

• (a) hydrolyzing a silicon compound in a flame to obtain fine glass particles, and depositing the fine glass particles to form a porous glass mass;
• (b) heating the porous glass mass in an atmosphere containing fluorine at a temperature of 1000.degree. to 1700.degree. C. to obtain a fluorine-doped porous glass mass;
• (c) consolidating the fluorine-doped porous glass mass in an atmosphere containing fluorine at a temperature of not less than a softening point of said pourous glass mass to obtain a fluorine-doped synthetic silica glass;
• and
• (d) heating the fluorine-doped synthetic silica glass in an atmosphere containing hydrogen gas at a temperature of not more than 500.degree. C. to obtain a synthetic silica glass doped with fluorine and hydrogen molecules.