Power excursion suppression in cascades of optical amplifiers with automatic maximum level control

The automatic maximum level control scheme, which automatically selects the maximum power channel as the control channel and keeps its maximum power constant, is the most attractive candidate among gain control techniques applicable to wavelength-division-multiplexed linear repeaters. The design guidelines of this scheme are presented. The power transient response and bit-error-rate performance of the remaining channels during changes in the number of channels are measured in cascades of four repeaters. It is experimentally confirmed that power excursions and power penalties at the bit-error rate of 10/sup -9/ can be suppressed to less than 0.7 dB and less than 0.3 dB, respectively, even when seven out of eight channels are dropped within 1 μs.