Numerical analysis of signal gain and noise figure of S-band Tm-doped W-type fibre amplifier with different pumping configurations

Abstract

A completely spectrally and spatially resolved theoretical model of a silica-host thulium-doped fibre amplifier is presented. In contrast to the models reported so far, multimodal structure of emission is taken into account. Several promising pumping schemes are considered. Genetic algorithm is implemented for pumping scheme optimization to attain the maximum gain or minimum gain ripple. W-type and step-index fibre performance is compared. The results obtained allow to select the best parameters for each considered scheme. Keywords: thulium-doped fibre amplifier, W-type fibre, genetic algorithm