| 摘要 |
PURPOSE:To produce the title parent material being free from staining on the glass rod surface before soot deposition and giving optical fiber of reduced optical loss, by depositing glass fine particles on a surface-treated glass rod and heating them into clear glass in a specific unit. CONSTITUTION:A seed rod 4, a glass rod which is held at the top end and hung down, is surface-treated in the first tightly closed furnace 2 and transferred into chamber 3 where fine particles of quartz glass are formed by introducing silicon tetrachloride into oxyhydrogen flame on the burner 31 and deposited around the surface-treated seed rod 4. Thus, a composite preform consisting of the glass rod and the glass fine particles is prepared. Then, the seed rod 4 of the preform is heated in the furnace 1 to effect elimination of remaining hydroxyls groups and clarification of the glass. |
