Link-control gain clamping for a cascaded EDFAs link using differential ASE monitor

We propose a novel scheme for the suppression of gain excursion in a cascad ed erbium-doped fiber amplifiers (EDFAs) link, By applying the differential amplified spontaneous emission monitoring method on link-control gain clam ping, it is possible to achieve gain clamping for the whole link irrespecti vely of the control-signal wavelength and characteristics of individual amp lifiers, The suggested algorithm/circuitry does not require predefinition o f the injected signal power and operates independently of the wavelengths o f control/data signals to the EDFA, enabling its application to different a mplified links under distinct design parameters.