Patent ID: 8257612

Claim:
A composition comprising (a) a host material selected from the group consisting of Y 2 O 3 , Y 2 GdAl 5 O 12 , Y 3 Al 5 O 12 , Y 3 Al 4 GaO 12 , YBO 3 , Y 0.76 Gd 0.24 BO 3 , YPO 4 , Y 2 SiO 5 , LaBO 3 , LaPO 4 , La 2 O 3 , LaAlO 3 , LuAlO 3 , La 3 Al 5 O 12 , La 2 SiO 5 , ZnB 2 O 4 , a glass, SrAl 2 O 4 , a sulfide, a fluoride, an oxynitride, an oxysulfide, an oxyfluoride, a borosilicate, a thioaluminate, a thiogallate, a germinate, a stannate, a vanadate, a molybdate, a tungstate, and ReP 5 O 14 , where Re is a rare earth element; (b) a first dopant comprising Yb; and (c) a second dopant comprising Ce, wherein the composition has a first response to a first electromagnetic radiation and, after intermediate exposure to a second electromagnetic radiation, a second response to the first electromagnetic radiation, different from the first response, and wherein the composition comprises agglomerated nanoparticles.