| 摘要 |
PURPOSE:To enable uniform heating over a wide range and to lower loss by interposing a shielding plate between an optical fiber and burner and subjecting the fiber to indirect heating. CONSTITUTION:The shielding plate 3 is provided between the optical fiber 1 and the burner 2. The shielding plate 3 is heated by the convection heating by the burner 2 and the optical fiber 1 is heated indirectly by the radiation heating according to the temp. elevation of the shielding plate 3. The heating range of the optical fiber 1 is, therefore, expanded and the undesirable deformation of the molten part of the fiber by the wind pressure of the flame of the burner 2 is prevented. The desired temp. distribution of the optical fiber by the radiation heating of the shielding plate 3 is obtd. by previously adequately setting the shape such as thickness distribution of the shielding plate. The excess loss is thereby decreased. |
