A transmission link for transmitting an optical signal including a plurality of wavelength channels, said optical signal having a bandwith of 25nm - 120nm, the transmission link comprising: an optical fiber span that is 60km - 120km long for propagating the optical signal therein from a first end to a second opposed end thereof; first and second WDM combiners optically coupled to the first and second ends of the optical fiber span, respectively, for coupling pump light there into; first and second pump subassemblies optically coupled to the first and second WDM combiners, respectively, for providing the pump light, the first and second pump subassemblies each comprising: first and second first-order Raman pumps for providing first-order Raman pump light for amplifying the optical signal; and first and second second-order Raman pumps for providing second-order Raman pump light for amplifying the first-order Raman pump light; wherein the emission wavelengths of each Raman pump in the first and second pump subassemblies differ from each other, and wherein the second pump subassembly comprises: a first WDM splitter optically coupled to the second end of the optical fiber span for splitting off a portion of residual pump light propagated through the optical fiber span from the first pump subassembly; a first photodetector optically coupled to the first WDM splitter for receiving the residual pump light portion and generating a first electrical signal in response to the residual pump light portion; and a controller operationally coupled to the first photodetector and each Raman pump of the second pump subassembly, characterized in that the controller has stored therein a first look-up table of values of the first electrical signal and associated power levels of each Raman pump of the second pump subassembly, and in that the controller is configured to dynamically adjust power levels of each Raman pump of the second pump subassembly in dependence upon the first electrical signal generated by the first photodetector based on the first look-up table, so as to lessen the peak-to-peak variation of the optical power of each one of the wavelength channels along the optical fiber span to less than 5dB. an optical fiber span that is 60km - 120km long for propagating the optical signal therein from a first end to a second opposed end thereof; first and second WDM combiners optically coupled to the first and second ends of the optical fiber span, respectively, for coupling pump light there into; first and second pump subassemblies optically coupled to the first and second WDM combiners, respectively, for providing the pump light, the first and second pump subassemblies each comprising: first and second first-order Raman pumps for providing first-order Raman pump light for amplifying the optical signal; and first and second second-order Raman pumps for providing second-order Raman pump light for amplifying the first-order Raman pump light; first and second first-order Raman pumps for providing first-order Raman pump light for amplifying the optical signal; and first and second second-order Raman pumps for providing second-order Raman pump light for amplifying the first-order Raman pump light; a first WDM splitter optically coupled to the second end of the optical fiber span for splitting off a portion of residual pump light propagated through the optical fiber span from the first pump subassembly; a first photodetector optically coupled to the first WDM splitter for receiving the residual pump light portion and generating a first electrical signal in response to the residual pump light portion; and a controller operationally coupled to the first photodetector and each Raman pump of the second pump subassembly, characterized in that the controller has stored therein a first look-up table of values of the first electrical signal and associated power levels of each Raman pump of the second pump subassembly, and in that the controller is configured to dynamically adjust power levels of each Raman pump of the second pump subassembly in dependence upon the first electrical signal generated by the first photodetector based on the first look-up table, so as to lessen the peak-to-peak variation of the optical power of each one of the wavelength channels along the optical fiber span to less than 5dB.