| 摘要 |
PURPOSE: To obtain a multilayered optical fiber having a high refractive index and good propagation characteristic by subjecting a core to a doping treatment with germanium dioxide and subjecting a first jacket to a doping treatment with fluorine. CONSTITUTION: This optical fiber is composed of the elliptic core 1 and the elliptic two jackets, i.e., the inner jacket 2 and the outer jacket 3. The core 1 of this optical fiber is produced from quartz glass. The refractive index of the core 1 of the optical fiber is increased by the doping treatment using the germanium dioxide and is reduced to the value smaller than the refractive index of the core 1 by the doping treatment using the fluorine. The jacket 3 on the outer side of the first jacket 2 subjected to the doping treatment with the germanium dioxide and the fluorine or is preferably composed of the quartz glass alone. The multilayered optical fiber having an elliptic sectional shape in such a manner has the preferable propagation characteristic and maintains the polarized light of a basic mode. |
