YTTERBIUM-DOPED OPTICAL FIBER, FIBER LASER, AND FIBER AMPLIFIER

摘要

Disclosed is an ytterbium-doped optical fiber comprising a core and a clad which surrounds the core, wherein the core contains ytterbium, aluminum and phosphorus and does not contain germanium.  In the core, ytterbium is contained in an amount of 0.09 to 0.68 mol% in terms of ytterbium oxide content, the molar ratio of the content of phosphorus (in terms of diphosphorus pentaoxide content) to the content of ytterbium (in terms of ytterbium oxide content) is 3 to 30, the molar ratio of the content of aluminum (in terms of aluminum oxide content) to the content of ytterbium (in terms of ytterbium oxide content) is 3 to 32, and the molar ratio of the content of aluminum (in terms of aluminum oxide content) to the content of phosphorus (in terms of diphosphorus pentaoxide content) is 1 to 2.5.