| 摘要 |
PURPOSE:To provide the optical fiber which has an ideal profile in the refractive index distribution between a core part and a clad part and can prevent the increase in the light transmission loss particularly against bending of the fiber and the process for production of such fiber. CONSTITUTION:The concn. of the fluorine to be doped to the core part 2 is radially nonuniformized (is made high in the central part and low in the core part). Consequently, the refractive index distribution of the core part 2 and the clad part 4 before a stage for vitrification to transparent glass is the profile high in the outer peripheral part of the core part 2 and low in the central part. The decrease in the refractive index in the outer peripheral part of the core part by the diffusion of GeO2, etc., as the oxide included in the core part at the time of the stage for vitrification to transparent glass is, therefore, corrected and eventually, the refractive index distribution of the care part 2 is the distribution protruding stepwise to the clad part 4. |
