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