Application of the differential ASE power monitoring approach to the cascaded EDFA´s link-control gain clamping method

We propose a novel scheme for the suppression of gain excursion in an EDFA´s link. By applying the differential ASE monitoring method on link-control gain clamping, we simultaneously achieve gain clamping for the link irrespective of control signal wavelength and characteristics of individual amplifiers. This algorithm/circuitry does not require pre-scaling on the total signal injection power or wavelength to the EDFA, and is universally applicable to different links at various design parameters.