As a result, {HEAD ~ the thickness} of glass plate 203 must be precisely controlled so that there is minimal optical path length difference between {TAIL ~ the two beam components} 233, 234 
As a result , { HEAD ~ the thickness } of glass plate 203 must be precisely controlled so that there is minimal optical path length difference between { TAIL ~ the two beam components } 233 , 234
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH