FLUORESCENT GLASS, PRODUCTION METHOD OF FLUORESCENT GLASS, OPTICAL FIBER AND FIBER LASER

摘要

PROBLEM TO BE SOLVED: To suppress occurrence of photo-darkening.SOLUTION: A fluorescent glass (10) contains quartz, a rare earth element, and at least one of alkaline-earth metal and alkaline metal. In terms of the oxide, molar ratio of at least one of alkaline-earth metal and alkaline metal is larger than that of rare earth element. The alkaline-earth metal preferably contains calcium, and the rare earth element preferably contains ytterbium. In the fluorescent glass (10), quartz preferably has a largest weight ratio or molar ratio, when compared with rare earth element, and at least one of alkaline-earth metal and alkaline metal.