Net gain of 15.5 dB from a 5.1 cm long Er/sup 3+/-doped phosphate glass fiber

Abstract

New erbium-doped phosphate glasses and fibers were fabricated. A net gain of 15.5 dB at 1535 was achieved from 5.1 cm long fiber, which represents the highest gain per unit length for fiber amplifiers to the best of our knowledge.