Performance reduction and design modification of erbium-doped fiber amplifiers resulting from pair-induced quenching

Abstract
The authors model the deleterious effect of pair-induced quenching (PIQ) in erbium-doped fiber amplifiers (EDFAs) and describe it in terms of pump power, amplification, and noise factor penalties. With a simple model of how PIQ increases with concentration, they show that to achieve a desired amplification, shorter fiber lengths will require higher pump power, and that there is a lower length limit with realistic pump powers. Rate equations for erbium-ion pairs are formulated with the assumption of one ion per pair completely quenched. Although the results were obtained for EDFAs, the methods and conclusions are also relevant for high-concentration erbium-doped integrated waveguides.