A method for manufacturing {HEAD ~ an infrared filter} 11 wherein {TAIL ~ said coatings} are composed of either PbF2 or ThF4 
wherein
A method for manufacturing { HEAD ~ an infrared filter } 11 wherein { TAIL ~ said coatings } are composed of either PbF2 or ThF4
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH