| 摘要 |
PROBLEM TO BE SOLVED: To easily materialize an optical fiber and an optical transmission medium which can transmit light in a single mode while reducing both macro bending loss and PMD. SOLUTION: In the optical fiber 1, a clad portion 8 having a refractive index lower than that of a core portion 2 is provided on the outer circumference of the core portion 2. The clad portion 8 has a first clad 3 where a plurality of sub-medium portions 5a-5d, 6a-6h are arranged in multilayer. For example, in the inside clad region 3a of the first clad portion 3, the sub-medium portions 5a-5d having a refractive index lower than that of the main medium portion at the first clad portion 3 are arranged at respective four rotationally symmetric positions around the core portion 2 in the first clad portion 3 and, in the outside clad region 3b, the sub-medium portions 6a-6h having a refractive index lower than that of the main medium portion at the first clad portion 3 are arranged at respective four rotationally symmetric positions around the core portion 2 in the first clad portion 3. COPYRIGHT: (C)2007,JPO&INPIT |
