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