| 摘要 |
PURPOSE:To suppress the generation of precursor of glass defect seeds in an optical fiber in the melt-spinning of an optical fiber preform, by carrying out the spinning while irradiating the preform and/or the optical fiber with light. CONSTITUTION:The lower end of an optical fiber preform 1 having a top end 4 cut perpendicular to the axis is inserted into a heating furnace 2, heated, melted and spun to obtain an optical fiber 3. At the same time, the top end 4 of the optical fiber preform 1 is irradiated with light from a light source 5 and the light is transmitted through the core and the clad of the preform 1 to the molten part of the preform 1 and the optical fiber 3 connected to the molten part. The strain liable to remain in the glass can be relaxed by the light excitation and deactivation to prevent the generation of the precursors of glass defect seeds. Accordingly, an optical fiber which can be used in a severe environment without causing the increase in the transmission loss can be produced. |
