Another example of improvement in {HEAD ~ structure} of {TAIL ~ an optical element} is shown in FIG 11 
of
Another example of improvement in { HEAD ~ structure } of { TAIL ~ an optical element } is shown in FIG 11
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH