| 摘要 |
<p>The present invention relates to a method for production of a synthetic quartz glass having a fluorine concentration of 1,000 ppm by mass or higher, comprising the following steps (a) to (c): (a) depositing and growing quartz glass fine particles obtained by flame hydrolysis of a glass-forming material onto a substrate, to thereby form a porous glass body; (b) maintaining the porous glass body in a reaction vessel under an elemental fluorine (F 2 )-containing atmosphere of a pressure of P b1 and a temperature of 400°C or lower, and followed by maintaining in the reaction vessel under condition of a pressure P b2 lower than the pressure P b1 and a temperature of 400°C or lower, to thereby obtain a fluorine-containing porous glass body; and (c) heating the fluorine-containing porous glass body in a vitrification furnace to a transparent vitrification temperature, to thereby obtain a fluorine-containing transparent glass body.</p> |
