Optical fiber for optical amplifier and fiber optic amplifier

摘要

An optical fiber for optical amplification used for 1.58 mum band signal light amplification, at least a core region thereof being doped with Er has a core region at least a part thereof made of silica glass co-doped with Ge and Al together with Er, and Er average atomic concentration in the core region is from 1000 wt-ppm to 3000 wt-ppm inclusive, and cutoff wavelength is from 1.3 mum to 1.5 mum inclusive.