TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The photoluminescent nanoparticles comprise material chosen from cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc sulfide, zinc telluride, indium nitride, indium phosphide, aluminum-gallium arsenide, indium-gallium arsenide, copper sulfide, silver sulfide, copper-indium selenide, copper-indium sulfide, indium sulfide, gallium phosphide, indium phosphide, gallium nitride, aluminum nitride, gallium arsenide, lead sulfide, lead selenide, lead telluride, copper chloride, copper sulfide, copper selenide, copper-zinc-tin sulfide, copper-zinc-tin selenide, copper-zinc-tin telluride, copper-indium telluride, silicon, germanium, yttrium oxide, yttrium sulfide, yttrium selenide, sodium-yttrium fluoride, sodium-yttrium sulfide, lanthanum fluoride, yttrium fluoride, zinc oxide, titanium dioxide, lanthanum oxysulfide, yttrium oxysulfide, gadolinium oxysulfide, zinc nitride, zinc sulfide and their alloys. The photoluminescent nanoparticles further comprises passivation layer, wide-gap nanocrystals, polymeric molecules, inorganic molecules and capping molecules. The passivation layer comprises passivation material chosen from cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc sulfide, zinc telluride, indium nitride, indium phosphide, aluminum-gallium arsenide, indium-gallium arsenide, copper sulfide, silver sulfide, copper-indium selenide, copper-indium sulfide, indium sulfide, gallium phosphide, indium phosphide, gallium nitride, aluminum nitride, gallium arsenide, lead sulfide, lead selenide, lead telluride, copper chloride, copper sulfide, copper selenide, copper-zinc-tin sulfide, copper-zinc-tin selenide, copper-zinc-tin telluride, copper-indium telluride, silicon, germanium, yttrium oxide, yttrium sulfide, yttrium selenide, sodium-yttrium fluoride, sodium-yttrium sulfide, lanthanum fluoride, yttrium fluoride, zinc oxide, titanium dioxide, lanthanum oxysulfide, yttrium oxysulfide, gadolinium oxysulfide, zinc nitride, zinc sulfide and their alloys. The inorganic molecules are chosen from tetrafluoroborate ion, sulfide ion, hydrosulfide ion, divalent selenium ion, hydrogen selenide ion, divalent telluride ion, hydrogen telluride ion, tellurium sulfide ion, hydroxide ion, ammonia ion, indium-selenide ion, tin-telluride ion, arsenic sulfide ion, chalcogenidometalate (Sn2S64-) and thiocyanate ion. The atom or cluster of atoms is chosen from manganese, cobalt, copper, platinum, ruthenium, vanadium, chromium, silver, gold, aluminum, bismuth, antimony, chlorine, bromine or iodine, cerium, praseodymium, neodymium, samarium, europium, terbium, dysprosium, holmium, erbium, thulium, and ytterbium, preferably manganese. The amount of defects is 10 mol% or less, preferably 1 mol%. The wide-gap nanocrystals are chosen from sodium-yttrium fluoride, gadolinium oxysulfide, sodium-yttrium sulfide, yttrium sulfide and cerium orthophosphate. The wide-gap nanocrystals comprise dopant containing ytterbium. The photoluminescent nanoparticles are chosen from manganese-doped zinc selenide/zinc sulfide/cadmium sulfide/zinc sulfide, copper-doped indium phosphide/zinc sulfide, zinc-cadmium-manganese selenide/zinc sulfide (Zn1-x-yCdxMnySe/ZnS, where x and y are 0.1), ytterbium-doped silicon/silicon dioxide, ytterbium-doped sodium yttrium fluoride/cadmium selenide/zinc selenide, copper-zinc-indium selenide (CuxZnyInzSe2-c, where y:z is 0-0.5, x/(y+z) is 0.05, and c is not defined), and ytterbium-doped cadmium telluride/zinc sulfide. The photoluminescent nanoparticles have an average maximum dimension of 10 nm or less.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The capping molecules are chosen from amine, carboxylate, phosphonate, phosphine, phosphine oxide, oligomeric phosphine, thiol, dithiol, disulfide and nitrogen-containing heterocycle, preferably chosen from dodecylamine, trioctylamine, oleylamine, trioctylphosphonate, trioctylphosphine oxide, trioctylphosphine, pyridine, acetate, stearate, myristate and oleate. The capping molecules contain reactive functional group chosen from olefin, silane, acrylate and epoxide. The polymeric molecules comprises a side chain comprising moiety chosen from phosphine, phosphine oxide, phosphonate, phosphine oxide, pyridine, amine, amide, carboxylic acid, carboxylate and thiol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The waveguide material is chosen from polyacrylate, polycarbonate, inorganic glass, polycrystalline solid, amorphous solid, cyclic perfluorinated polyether, polysilicone, polysiloxane, polyalkylacrylate and cyclic olefin, preferably poly(methyl methacrylate), poly(lauryl methacrylate) or their crosslinked derivatives. The waveguide material has a surface roughness of 2 nm or less. The amount of waveguide material is less than 10 wt.%.