Patent ID: 8363313
Filing Date: 2013-01-29
Classification: C03C,G02B,H01S

Abstract:
1. An ytterbium-doped optical fiber comprising: a core which contains ytterbium, aluminum, and phosphorus, and does not contain germanium; and a cladding which surrounds this core, wherein: the ytterbium concentration in the core in terms of ytterbium oxide is 0.09 to 0.68 mole percent; a molar ratio between the phosphorus concentration in the core in terms of diphosphorus pentoxide and the ytterbium concentration in the core in terms of ytterbium oxide is 3 to 30; a molar ratio between the aluminum concentration in the core in terms of aluminum oxide and the ytterbium concentration in the core in terms of ytterbium oxide is 3 to 32; a molar ratio between the aluminum concentration in terms of aluminum oxide and the phosphorus concentration in terms of diphosphorus pentoxide is 1 to 2.5, and the relative refractive index difference between the core and the cladding is 0.1 to 0.25%.