In which case, the substrate is thick enough to stretch the thin films to offset temperature related changes in {HEAD ~ optical thickness} of {TAIL ~ the films}, but it is not so thick that it overcompensates these changes 
In which case , the substrate is thick enough to stretch the thin films to offset temperature related changes in { HEAD ~ optical thickness } of { TAIL ~ the films } , but it is not so thick that it overcompensates these changes
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH