Evaluation of transient dynamic impact in gain controlled EDFAs

In this paper, the EDFA transient behavior was experimentally characterized in terms of the Q factor following severe amplifier input power variations. The performance was observed for a conventional EDFA and for optically and electronically (feedforward and feedback modes) gain-controlled EDFAs. Estimations of the Q factor were obtained by an error analyzer in burst mode after the delay of a gate pulse had been varied within the amplifier response time interval. Electronically controlled EDFAs in booster applications showed severe penalties during transients whilst optically controlled EDFAs as in line amplifiers were able to practically keep the Q factor unchanged during input power variations.