{HEAD ~ At least two multiplexers} are used for assembling {TAIL ~ respective multiplexed output signals} and are connected by an array of semiconductor optical amplifiers , each channel having correspondingly at least two SOAs connecting it respectively to each of the multiplexers 
are used for assembling
{ HEAD ~ At least two multiplexers } are used for assembling { TAIL ~ respective multiplexed output signals } and are connected by an array of semiconductor optical amplifiers , each channel having correspondingly at least two SOAs connecting it respectively to each of the multiplexers
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH