In either arrangement, {HEAD ~ the reflective layer} has {TAIL ~ an associated center wavelength}, which is substantially independent of temperature 
has
In either arrangement , { HEAD ~ the reflective layer } has { TAIL ~ an associated center wavelength } , which is substantially independent of temperature
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH