Optical fiber and optical amplifier

Abstract

An optical fiber includes: a core region that is doped with a rare-earth ion; an adjustment region that is constituted by either a hole or a glass rod and is arranged in such a way as to have a central axis parallel to a central axis of the core region; and a cladding region that is arranged in such a way that the core region and the adjustment region are included inside the cladding region, wherein the adjustment region is arranged at a position deviated in an anisotropic manner as viewed from a central axis of the cladding region.

Dependencies are inferred from the claim text.