A thickness of {HEAD ~ the same substrate} may determine a numerical aperture of {TAIL ~ the optical element} 
A thickness of { HEAD ~ the same substrate } may determine a numerical aperture of { TAIL ~ the optical element }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL