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