Tutorial on Fundamental Limitations of EDFAs in Amplified Transmission Systems

Summary form only given. This tutorial outlines various factors in erbium-doped fiber amplifiers (EDFAs) causing fundamental limitations in lightwave transmission systems, linear propagation being primarily assumed. It is divided in two parts. In the first, we recall definitions for spectral inversion and gain, noise figure, SNR and Q-factor, as related to optical amplifier chains; saturation-induced effects on EDFA bandwidth are also considered. The second part is concerned by practical limitations in bandwidth, noise figure and output power, and related technologies enabling their minimization (gain equalization, multiple-stagehybrid pumping, glass hosts).