Consistent with the present invention, {TAIL ~ an optical filter} is provided comprising a single crystal or crystalline quartz substrate and a reflective layer provided on {HEAD ~ the quartz substrate} 
Consistent with the present invention , { TAIL ~ an optical filter } is provided comprising a single crystal or crystalline quartz substrate and a reflective layer provided on { HEAD ~ the quartz substrate }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD