Computational studies of light-matter interactions in two- and three-dimensional systems

• Main Author: Little, Claire Elspeth
• Published: Durham University 2011
• Subjects: 535
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.545636

A computational approach is taken to studying a range of light-matter interactions which are interesting in terms of their potential applications as well as from a fundamental point of view. Two different types of polariton, part-light, part-matter quasiparticles, namely exciton-polaritons and Tamm plasmon-polaritons (a type of surface plasmon-polariton) are considered. The conditions required for the strong coupling of optical whispering gallery modes and bulk excitons in submicron spheres are ascertained for the materials gallium arsenide, gallium nitride and zinc oxide. It is shown that the strong coupling regime may be accessed by optical modes with a low decay constant, typically exhibited by those modes with higher angular momentum quantum numbers. Tamm plasmon-polaritons have previously been shown to exist at the boundary between a metal and a planar Bragg reflector structure. The conditions required for the formation of Tamm plasmon-polaritons in cylindrical multilayer structures with a metal core, cladding or metal in both of these locations are determined. The cylindrical Tamm plasmon-polaritons are shown to have low effective masses and low group velocities. It is also shown that it is possible to obtain split polariton modes in structures containing metal in both the core and the cladding. The effect of disorder on a two-dimensional photonic crystal structure consisting of air holes in a slab of dielectric material is studied. It is shown that the defined threshold disorder is not signicantly affected by the dierent relative band widths of the ideal crystal structures considered.