| 摘要 |
PURPOSE:To obtain a parent material for optical fiber having high quality by heating a glass soot material consisting principally of quartz in gaseous atmosphere contg. elements for adjusting the refractive index while moving the glass soot material under specified conditions to cause contraction and vitrification of the glass soot material. CONSTITUTION:A parent material for glass soot consisting principally of quartz is heat-treated in gaseous atmosphere contg. elements for adjusting refractive index, thus adding said element to the parent material for glass soot. In this process, the parent material for the glass soot is moved slowly in said gaseous atmosphere to cause contraction and vitrification from one end of the parent material to another end, wherein the direction of the movement of the parent material is regulated to coincide with the direction of the flow of the gaseous atmosphere. Suitable parent material for the glass soot is prepd., for example, by introducing feed material for the glass together with additive gas, etc., using inert gas as carrier into flame, and depositing fine glass particles formed by flame hydrolysis. |
