| Photonic crystals,namely photonic bandgap materials,are artificially arranged periodic electromagnetic structure in optical wavelength scale. Due to the periodic modulation of the refraction index, they possess photonic band gaps that inhibit the existence of light in certain frequency ranges, which is analogous to what the semiconductor do to the electrons. In the last decade, photonic crystals have been a rapidly developing field because of their novel optical properties and important potential applications. It also does not present the complete photonic bandgap(PBG) owing to the low rwfractive index(RI) and low RI contrast of the components. To realize the complete PBD and to rich the propertiea of PCs, an effective route is to mix of different materials into the three-dimensional (3D) ordered structures. There are two main ways to make the composites: by synethesizing composite spheres prior to buliding the PCs(so-called as bottom-up route) or by synthesing new materials in or around the pores of an assemble opal (so-called as top-down route).This dissertation focouses on multilayer photonic crystal for spectral narrowing of emission, inverse opal-like crystal of liquids and refractive index doping of photonic crystals.A quaternary system, consisting of air, an air-core/dense-silica-shell core-shell particle, and liquids has been used to fabricate an inverted opal structure with low fill factor, high refractive index contrast and reversible tuning capabilities of the bandgap spectral position. The original close-packed opal structure is a ternary self-assembled photonic crystal from monodisperse and spherical polystyrene-core/silica-shell colloidal particles with air as the void material. Calcination removed the polystyrene and converted the core-shell particles to hollow spheres with a dense shell. In a final step, liquid is infiltrated only in the voids between the hollow spheres, but does not penetrate in the shell. This allows facile and reversible tuning of the bandgap properties in an inverted opal structure.Multilayer colloidal crystal has been prepared by the layer-by-layer deposition of silica microspheres on a glass slide. Each layer is a slab consisting of a fcc close-packed colloidal arrays. By properly choosing the sizes of spheres, the whole spectral feature of multilayer colloidal crystal can be tuned. Here, we engineered a multilayer superlattice structure with an effective passband between two stop bands.This gives a strong narrowing effect on emission spectrum. With the stop bands at the shortwave and longwave edges of emission spectrum, the passband in the central wavelength region can be regarded as a strong decrease of suppression effect and enhancement of a narrow wavelength region of emission. The spectral narrowing modification effect of suitably engineered colloidal crystals shows up their importance in potential application as optical filters and lasing devices.One of the structures that can be fabricated using heterostructure is obtained by inserting a low-band-gap semiconductor between two higher-gap materials.In face, it has destroied face-centered cubic(FCC) structure of photonic crystals,and can not prove the theory about the defect.We choose silica hollow spheres as defect inserting colloid crystals, which have different dielectric constant with silica spheres. By successively depositing a multilayer crystal using convective self- assembly and then deposition a single layer using Langmuir-Blodgett(LB) technique and, finally, again depositing a multilayer ,we succeeded in introducing a microcavity into a self-assembled crystal. There are obviously stopband in spectrum.
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