Patent ID: 7251071

Claim:
A method for operating an optical transmission system having a link capable of carrying a plurality of optical channels of different wavelengths traveling along the link in a downstream direction, the method comprising: tapping, at an initial time, an initial optical signal from the link using an optical tap connected to the link; measuring, using an optical monitor, an initial total optical power level for the tapped initial optical signal for wavelengths corresponding to at least two of the optical channels; tapping, at a subsequent time after the initial time, a subsequent optical signal from the link using the optical tap; measuring, using the optical monitor, a subsequent total optical power level for the tapped subsequent optical signal for the wavelengths corresponding to the at least two optical channels using the optical monitor; measuring a change in total optical power level for the wavelengths corresponding to the at least two optical channels by comparing the measured initial total optical power level and the measured subsequent total optical power level; and adjusting pump power levels of a plurality of optical pumps in the optical transmission system, wherein: the plurality of optical pumps are connected in series along the link to inject optical signals into the link in a single direction; if the optical pumps inject optical signals in the downstream direction, then the optical tap is connected downstream of the plurality of optical pumps; if the optical pumps inject optical signals in an upstream direction, then the optical tap is connected upstream of the plurality of optical pumps; adjusting the pump power level of a first of the optical pumps affects a first set of the optical channels; adjusting the pump power level of a second of the optical pumps affects a second set of the optical channels having a different set of wavelengths from the first set of the optical channels; the adjustment for each optical pump is a function of (i) the measured change in the total optical power level and (ii) a specified transient-control model for the optical pump; and two or more of the optical pumps have different specified transient-control models such that different adjustments are made to the pump power levels of the two or more optical pumps based on the measured change in the total optical power.