| 摘要 |
<p>This optical fiber is provided with a core (31), a cladding part (32) surrounding the periphery of the core and having a dopant-added region (32a) to which a dopant is added, and a plurality of vacancies (33) provided in the cladding part parallel to the core and concentrically with the core. When the diameter of the vacancies is defined as d1, the relative refractive index differences of the dopant-added region with respect to pure quartz glass in an inside portion close to the core and an outside portion distant from the core at a boundary between the vacancies and the dopant-added region are defined as Deltarin and Deltarout, respectively, and (Deltarout - Deltarin)/d1 is defined as the percent of slope k of a refractive index profile in the dopant-added region, the vacancies are provided in a region of the dopant-added region where the percent of slope k is -0.05%/µm to 0.05%/µm. This optical fiber makes it possible to suppress positional misalignment of the vacancies.</p> |
