Per-band link control transients protection in distributed fiber Raman amplifier cascades

In this work we introduce the use of the per-band link control method in cascades of distributed fiber Raman amplifiers (DFRAs) for compensating power transients of WDM channels. By using two compensation channels, each one controlled by a proportional-integrative electronic control circuit and assigned to a particular signal band, the power excursion achieved in the surviving channels, in a cascade of 10 DFRAs, is reduced from 4.88 dB to 0.24 dB, when 17 out of 20 channels are added or dropped. By adding more compensation channels, this transient protection technique can be extended to wideband DFRAs applications.