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