Transient gain and cross talk in erbium-doped fiber amplifiers

Abstract

Transient gain saturation and recovery with 110-340-microsec time constants were observed in erbium-doped fiber amplifiers. This slow response reduces the effects of saturation-induced cross talk and intermodulation distortion associated with multichannel signal amplification. In a two-channel amplification experiment, negligible saturation-induced cross talk was measured at signal modulation frequencies >5 kHz. Increased suppression of saturation-induced cross talk was achieved through feed-forward compensation to reduce low-frequency gain fluctuations.