FIG 5A illustrates {HEAD ~ the intensity} of {TAIL ~ the received light} as a function of time 
of
FIG 5A illustrates { HEAD ~ the intensity } of { TAIL ~ the received light } as a function of time
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH