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