| 摘要 |
PURPOSE:To obtain optical fiber having less structural defect and having improved characteristics for retarding increase of transmission loss for long wavelength light by adding Cl as dopant to the core and/or the clad. CONSTITUTION:SiCl4 and GeCl4 using Ar as carrier gas is fed to the first passage at the center of a 4-layered concentric structure burner 4 for core, H2 to the second passage, Ar to the third passage, and O2 to the outermost fourth passage. On one hand, SiCl4 using Ar as carrier gas is fed to the first passage of a 4-layered concentric structure burner 5 for clad, H2 to the second passage, Ar to the third passage, and O2 to the outermost fourth passage. Fine glass particles generated by the flame hydrolysis are deposited and a parent material 8 for optical fiber having a core glass layer 6 and a clad glass layer 7 is obtd. Thereafter, the parent material 8 is inserted into a furnace core tube and transformed to vitrified transparent glass, and drawn by heating. Thus, optical fiber 1 contg. Cl as dopant in the core 2 and/or clad 3 is obtd. |
