SILICA GLASS WITH RARE EARTH METAL DOPING, AND PRODUCTION METHOD OF THE SAME

PROBLEM TO BE SOLVED : To provide an enhanced method which assures production of silica glass with rare metal doping showing reproducible characteristics, and the silica glass with rare metal doping, which shows a little refraction factor variation with excellent uniformity of chemical and electrical characteristics. SOLUTION : In the production method of the silica glass, a blank composed of the silica glass with rare metal doping is softened, and homogenized by twisting along with a rotation axis 10, and in so doing softened while applying oxidation plasma 5 or neutral plasma. Oxygen-containing gas, or hydrogen-containing or hydrogen non-containing compound is supplied to the plasma 5 by micro wave plasma or induction plasma. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2018, JPO&INPIT