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Abstract

Self-assembly is a promising approach for fabrication of 3D photonic crystals. The products known as opals contain, however, many internal defects. In this work one of fabrication methods, the capillary deposition method, was improved to obtain high quality opals. The opal structure (i.e. lattice orientation, domains, and cracks) was studied using microscopic and scattering techniques. The opal formation process was investigated using time-resolved UV/Vis-NIR spectroscopy. It allows the differentiation of opal formation stages including water redistribution and particle sintering. The optical properties of opals were probed using angle- and polarization-resolved spectroscopy. The shift of the different photonic peaks in the spectra can be well described using a kinematical interpretation, while their intensity variation satisfies a simplified dynamical diffraction model. It correlates the measured diffraction peaks with the band structures in higher Brillouin zones.