Self-assembled photonic crystals for a chemical sensing

As they allow the control of light propagation, photonic crystals find many fields of application. Among them, self-assembled 3D-photonic crystals are ordered at the nanometric scale over centrimetric areas. Furthermore, self-assembly allows the design of complexes structures leading, for example, to the controlled disruption of the crystal periodicity (called defect) and the appearance of permitted optical frequency bands within the photonic bandgap. Light frequencies included in the corresponding passband are then localized in the defect allowing manipulation of nano-emitters fluorescence. We present the fabrication and the optical characterization of a heterostructure composed of a sputtered silica layer sandwiched between two silica opals. We show by photoluminescence measurements than this structure strongly modifies the transmitted fluorescence of nanocrystals.