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