Patent ID: 7554719

Claim:
A Raman fiber amplifier that is responsive to N optical signal channels in an optical fiber system, comprising: M Raman pumps, each Raman pump injecting optical power into an optical fiber at an assigned pump frequency; a monitoring unit that provides an indication of an input signal power variation for at least one wavelength region, the N optical signal channels being associated with the at least one wavelength region; a control unit that determines a pump power adjustment for at least one Raman pump of the M Raman pumps using a predetermined function, the predetermined function comprising: Δ ⁢ ⁢ P L ⁡ ( j ) ≈ ∑ k = 1 K ⁢ T LL ⁡ ( j , k ) ⁢ Δ ⁢ ⁢ S L ⁡ ( k ) , wherein k corresponds to a k th wavelength region, K corresponds to a number of wavelength regions, j corresponds to a j th Raman pump, ΔS L (k) corresponds to the input signal power variation for the k th wavelength region as linearly scaled, ΔP L (j) corresponds to the pump power adjustment of the j th Raman pump as linearly scaled, and T LL (j,k) corresponds to a linear coefficient relating the pump power adjustment of the j th Raman pump and the input signal power variation for the k th wavelength region; the at least one Raman pump adjusting a power output in accordance with the pump power adjustment; and a calibration unit that configures the N optical signal channels, a signal power being different from a reference point only in the k th wavelength region, and that determines the linear coefficient T LL (j,k) by calculating ΔP L (j)/ΔS L (k).