Patent ID: 8105734

Claim:
A method for preparing a titania-doped quartz glass member, comprising the steps of: subjecting a silicon source gas feed and a titanium source gas feed to flame hydrolysis with the aid of a combustible gas and a combustion-supporting gas, to form synthetic silica fine particles; depositing the silica fine particles on a rotating target, and concurrently melting and vitrifying the particles to form quartz glass, thereby forming a titania-doped quartz glass ingot; placing the ingot in a shaping crucible which rotates in a furnace whose temperature distribution has a temperature gradient of at least 1.5° C./cm at 1,700° C.; shaping the titania-doped quartz glass in the crucible at 1,500 to 1,800° C. for 1 to 10 hours; holding the ingot at 700 to 1,300° C. in air for 1 to 200 hours for annealing; and slowly cooling the ingot down to 500° C. at a rate of 1 to 20° C./hr.