A filter of the type depicted in FIG 2 is suitable for infrared radiation in {HEAD ~ the spectral range} of {TAIL ~ wavelengths} from approximately 1.8 microns to 1000 microns 
of
A filter of the type depicted in FIG 2 is suitable for infrared radiation in { HEAD ~ the spectral range } of { TAIL ~ wavelengths } from approximately 1.8 microns to 1000 microns
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH