Date of Award
Doctor of Philosophy
Physics and Astronomy
C. M. Soukoulis
This thesis presents the results of numerical studies of scalar and electromagnetic wave propagation in periodic and random dielectric media. The photonic energy band structure of periodic composite materials, consisting of regular spherical arrays or scaffoldings of one kind of dielectric material in a different background material, are studied using the plane wave expansion method in order to determine, among other things, the optimum conditions (crystal structure, dielectric constant ratio, filling ratio etc.) for the existence of photonic band gaps. The significance of these numerical studies lies in the potential for important applications of photonic band gap materials and also in the difficulty of actually fabricating them. For random media we have used the Coherent Potential Approximation (CPA) method, based on scattering from a single sphere, to study classical wave propagation in random distributions of spheres of one material in another. The dielectric constant ratio and filling ratio are significant parameters here too and we study the behaviour of quantities such as the diffusion constant, mean free path and relevant velocities as functions of the frequency. These studies are relevant to the long-standing but as yet incompletely understood problem of localization for both classical and quantum waves.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Datta, Sreela, "Classical wave propagation in periodic and random media " (1994). Retrospective Theses and Dissertations. 10593.