| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber containing GeO2 not only in a core area but also in a clad area and having sufficient strength. SOLUTION: This optical fiber has a core area (a diameter 2a, a refractive index n), the first clad area (a diameter 2b, a refractive index n2) surrounding the core area and the second clad area (a refractive index n3) surrounding the first clad area, and the outside diameter is D (=2R). In this optical fiber, the diameter 2b of the first clad area is 0.80D to 0.98D. The diameter 2a of the core area is <80D. In this optical fiber based on silica glass, a GeO2 content g1 in the core area is >=1 wt.%, a GeO2 content g2 in the first clad area is >=1 wt.% and a GeO2 content g3 in the second core area is >0.2 wt.%. |
