Dye-containing polymer beads as photonic crystals

Monodisperse PMMA beads of a size varying between 200 and 400 nm have been prepared by a modified emulsion polymerization technique. These beads sedim ent well on substrates to form 3-dimensional face-centered cubic packages. This method allows it to cover large glass substrates (area up to 10 x 10 c m) with an opalescent layer of the beads thus creating films with opaline s tructure, which can be used as photonic crystals. Choosing PMMA as the mate rial of the beads brings several advantages, e.g., the PMMA photonic films can be precisely patterned by e-beam lithography with the feature resolutio n down to one bead in width and various fluorescent dyes can be incorporate d in PMMA balls. Dye-impregnated PMMA opaline photonic films demonstrate th e incomplete photonic band gap structure and related modification of dye ph otoluminescence spectrum.