{HEAD ~ The integrity} of a beam of light may be compromised by {TAIL ~ contamination} from other light beams giving rise to “cross talk” 
compromised by
{ HEAD ~ The integrity } of a beam of light may be compromised by { TAIL ~ contamination } from other light beams giving rise to “ cross talk ”
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH