OPTICAL FIBER FOR OPTICAL AMPLIFIER AND FIBER OPTIC AMPLIFIER

摘要

An optical fiber for optical amplification used for 1.58 .mu.m band signal light amplification, at least a core region thereof being doped with Er, wherein at least a part of the core region is made of silica glass co-doped with Ge and Al together with Er, and an average Er atomic concentration in the core region is from 950 wt-ppm to 3000 wt-ppm inclusive.