Patent ID: 7707855

Claim:
A method for producing synthetic quartz glass with a predetermined hydroxyl group content, the method comprising: (a) producing a porous SiO 2 soot body by flame hydrolysis or oxidation of a silicon-containing start compound and by layerwise deposition of SiO 2 particles on a rotating support; (b) subjecting the soot body to a dehydration treatment in a drying atmosphere containing a reaction gas at a drying temperature so as to remove for removing hydroxyl groups; and (c) vitrifying the SiO 2 soot body into a body comprising the synthetic quartz glass, wherein the dehydration treatment comprises a drying phase during which the reaction gas is ozone, wherein the drying atmosphere has an ozone content that is between 0.5% by vol. and 10% by vol., and the drying temperature is in a range between 1200° C. and 1400° C., and wherein no halogens are supplied to the drying atmosphere during the dehydration treatment.