Sintered, translucent ceramic microbeads, preferably alumina, titania, zirconia, yttria, zirconium phosphate, or {HEAD ~ yttrium aluminum garnet} are doped with {TAIL ~ one or more optically active species} 
doped with
Sintered , translucent ceramic microbeads , preferably alumina , titania , zirconia , yttria , zirconium phosphate , or { HEAD ~ yttrium aluminum garnet } are doped with { TAIL ~ one or more optically active species }
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 HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL