In response to a sudden change of input power, an EDFA withits control circuit will exhibit overshoot or undershoot in its outputsignal. This is called the transient response. With a typical EDFA,this transient response can last on the order of 100 μs. In a WDMtransmission line, the addition or removal of channels may causea transient, to which the EDFA must respond. The Super-Fast Erbium Doped Fiber Amplifier was developed to address these fasttransient conditions, with sub-μs suppression time.This EDFA is designed to be used in the traditional C-band. During operation, the signal wavelengths must be confined to a 3.2nm region for each optical amplifier, although the band may beanywhere within the C-band. The unit can work with up to 4 channels.