Fluorine-doped quartz glass article and manufacturing method thereof

Abstract

A method for manufacturing a fluorine-doped quartz glass article by sintering a porous glass preform moving in a heat zone in an atmosphere of a fluorine gas is disclosed, wherein a fluorine gas process is performed by setting a moving speed of the porous glass preform in the heat zone heated at 1000° C. or more in order that L/V is 40 minutes or more, where L is the length (mm) of a heater, and V is the moving speed (mm/min). The temperature of the heat zone may be vitrification temperature. The fluorine gas process may be performed in the heat zone which is at 1000° C. or more not to perform a vitrification process, and then the vitrification process maybe performed by increasing the temperature of the heat zone.

Dependencies are inferred from the claim text.