We present a scheme for tuning the photonic band gap (PBG) by an external electric field in a ferroelectric inverse opal structure. The inverse opals, consisting of ferroelectric (Pb,La)(Zr,Ti)O3 (PLZT) ceramics, were synthesized by a sol-gel process. Optical reflection spectra show that the PBG of the PLZT inverse opals shifts continuously with the change in the applied electric field. As the photonic crystals (PCs) consist of the high-refractive-index constituent and possess an "all-solid" structure, it should supply a more reliable mode to tune the PBG by the electric field for the superprism effect in PCs. It should be of high interest in device applications.

An optically transparent Ag nanorods/AAM composite film was prepared by AC electrodeposition of Ag within the nanoporous anodic alumina membrane (AAM). Because the incident light excited different surface plasmon resonance modes along different directions, the composite film displayed an optical anisotropy for the rod-shape of Ag particles. Its three-order nonlinear optical properties were measured by z-scan technique, and the values of |Rev(3)| and |Imv(3)| were about 2.6028

SiO2 colloid crystal infilled with BaTiO3 was synthesized by a process of self-assembly in combination of a sol-gel technique. It is found that infilling of the fully crystallized BaTiO3 into the colloid assembly can enhance the photonic band gap significantly. In the vicinity of the ferroelectric phase transition point of BaTiO3 (100-150℃), the photonic band gap of the assembly exhibits a strong temperature dependence. At the Curie point, the band gap has a 20nm redshift, and the optical transmittance reaches its minimum. Such a temperature-tuning effect in the photonic band gap should be of high interest in device applications.

A three-dimensional photonic band gap structure based on self-assembled crystals of polystyrene microspheres was fabricated by filling the pores with metallic silver. An almost complete stop band at 580-600 nm is observed in the optical transmission spectra. In comparison with pure polystyrene colloid crystals, the absorption band of Bragg diffraction in the composite was much more intense and broader, due to an enlargement of the contrast between the spheres and the background. A shift to shorter wavelengths in the band occurred because of a decrease in the average refractive index.

ZnS: Mn has been in-filled in photonic crystals of submicron polymer spheres. The effect of the photonic band gap on the photoluminescence (PL) properties of ZnS: Mn has been investigated. Because of the overlap of the transmission dip of the photonic crystal and the photoluminescence band of ZnS: Mn, both suppression and enhancement in the PL of the phosphor have been observed. A strong dependence of the fluorescence lifetime on the emission wavelength in the range of the stop band has been found. This strong dependence is believed to arise from the very low photon density of state within the stop band of the ZnS: Mn in-filled photonic crystal as result of a high dielectric contrast between ZnS: Mn and the polystyrene spheres.