| 摘要 |
PURPOSE:To form a porous base material at a high rate of deposition in a high yield of starting material when a gaseous starting material is spouted from an oxyhydrogen flame burner to deposit porous glass for a clad on the surface of a glass rod as a core material, by using another oxyhydrogen flame burner contg. no gaseous starting material. CONSTITUTION:When a quartz base material for an optical fiber is manufactured, a starting member 10 of quartz glass for forming a core part is rotated, and while slowly pulling up the member 10, a gaseous starting material for glass such as SiCl4, H2, O2 and Ar are spouted from an oxyhydrogen flame burner 13 to form a porous glass layer 11 for forming a clad part on the surface of the member 10 by hydrolysis in a flame. At this time, a general oxyhydrogen flame burner 15 contg. no SiCl4 is placed under the burner 13 to heat the underside of a soot forming flow 12 from the burner 13. The porous glass layer 11 can be formed at a high rate of deposition in a high yield of starting material. |
