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