| 摘要 |
PURPOSE:To obtain a single mode optical fiber having a low transmission loss and bending loss by coating the circumference of a central SiO2 core with F-SiO2 and further, coating the same with SiO2 of a specific thickness. CONSTITUTION:Fine particles of SiO2 glass are thinly deposited on a base material of SiO2 glass core/F-SiO2 glass clad and are heated in an electric furnace, by which said particles are vitrified to transparent glass. Such glass is drawn to form the single mode optical fiber. Wire tensile force F is shared by the previously fixed core 1b and the outermost layer 3a. The residual stress by sharing of the tensile force F by the core 1b is decreased to a substantially neglible level, if the thickness of the outermost layer 3a is selected in a 1-15mum range. A change in the transmission loss by a difference in the wire tensile force is hardly generated according to this constitution. Since the outermost layer is thin, said layer does not affect the transmission loss and does not deteriorate the bending loss characteristic. |
