| 摘要 |
<p>PURPOSE: To produce a base material-for optical fiber having high reflectance by depositing fine particles of glass that will form the inner layer clad and the core on the inner surface of a hollow glass tube to be the outer layer clad, clarifying them followed by solidification. CONSTITUTION: (1) A hollow glass tube 100 to be the outer layer clad is prepared, (2) fine particles of glass 110 are deposited on the inner wall of the glass tube 100 by introducing the glass-starting gas and a dopant-starting gas containing germanium and fluorine, as the tube 100 is heated and rotated, then, the glass tube 100 is heated at 1,700-1,800 deg.C to clarify the fine particles of glass whereby the glass layer to be the inner layer clad 111 is formed. (3) Then, the glass-starting gas and the dopant-starting gas are introduced, as the glass tube 100 is heated under rotation, to deposit fine particles of glass on the inner surface of the glass tube 100, and the glass tube 100 is heated up to 1,700-1,800 deg.C to clarify the glass fine particles whereby the glass layer to be the core 116 is formed. (4) Finally, the glass tube 100 is heated up to 1,700-2,100 deg.C to make the tube solid non-hollow, thereby the base material for optical fiber is obtained.</p> |
