Phononic properties of opals

Abstract

We study the vibrational properties of opals consisting of silica spheres stacked periodically. To analyze their characteristic features (frequency gaps etc.) we start from the calculation of eigenfrequencies of a single sphere and see how they are modulated when spheres are combined to form a single layer and then multiple layers stacked periodically. The theoretical band structure is compared with the vibrational spectra measured experimentally. © 2007 IOP Publishing Ltd.