Suppression of dynamic cross saturation in cascades of overpumped erbium-doped fiber amplifiers

Transient gain response of a cascade of optical amplifiers for addition/removal of channels represents a major problem in multiwavelength optical networks. In order to avoid error bursts in the surviving channels, signal power fluctuations due to channel addition or removal caused by network reconfigurations or line failures must be minimized. In this letter, we show that excellent suppression of both transient and steady-state signal power fluctuations due to channel addition/removal is achieved without additional measures if the concatenated erbium-doped fiber amplifiers (EDFA´s) are strongly inverted. The analysis is based on the application of a comprehensive large-signal numerical model that incorporates temporal properties of cascades of EDFA´s.