Bandgap of a three-dimensional dyed polystyrene photonic crystal from optical absorption

The role of a strong dye absorption in determining the photonic bandgap (PBG) shape of a three-dimensional dyed photonic crystal, fabricated from dyed polystyrene nanospheres, is investigated. When the dye absorption peaks fall on the PBG spectral position, the PBG has a distorted shape, narrow top, and wide bottom. Theoretical analysis shows that the characteristic PBG shape results from two superimposed contributions with distinct origins, i.e., a Bragg reflection and a high reflection associated with the strong dye absorption. (c) 2006 Optical Society of America