The substrates have a coefficient of thermal expansion that is greater than that of the dielectric layers, and {HEAD ~ the thicknesses} of {TAIL ~ the substrates} are selected to provide compensation for temperature dependant variations in the center wavelength of the filter 
of
The substrates have a coefficient of thermal expansion that is greater than that of the dielectric layers , and { HEAD ~ the thicknesses } of { TAIL ~ the substrates } are selected to provide compensation for temperature dependant variations in the center wavelength of the filter
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 OTH OTH OTH OTH