| 摘要 |
PURPOSE:To considerably improve the transmission loss characteristics of an optical fiber by using a gaseous mixture of a gas other than O2 with Ar as a plasma flame generating gas and by generating a plasma flame to fire-polish a central preform when a preform for an optical fiber is produced. CONSTITUTION:When a preform for an optical fiber is produced, a gaseous mixture of a gas other than O2, e.g., He, Ne, N2, CF4 or SF6 with Ar is used as a plasma flame generating gas and plasma flame is generated to fire-polish the surface of a transparent glass rod forming a central preform. Fine glass particles are then deposited on the periphery of the central preform, dehydrated and sintered to obtain a transparent glass rod. |
