Fluorescence-based measurement of g/sup */(/spl lambda/) for erbium-doped fluoride fiber amplifiers

We report a direct measurement of the gain coefficient g/sup */(/spl lambda/) for an erbium-doped fluoride fiber from the longitudinal fluorescence spectrum of a 980-nm-pumped amplifier. Measurements of the absorption coefficient /spl alpha/(/spl lambda/) and the saturation parameter /spl xi/ are also reported. The fluorescence-based g/sup */(/spl lambda/) is compared with the functional dependence predicted by McCumber theory.