Wideband absorbers in the visible spectrum based on optimizing quasicrystal nanosphere arrays

Optical properties of aperiodic aggregates of gold nanospheres are studied. The optical response of these arrays can be explained in terms of the grating response of the array (photonic resonance) and the plasmonic response of the spheres (plasmonic resonance). In particular the couplings between the photonic and plasmonic modes are studied. In periodic arrays this coupling leads to the formation of a so called photonic-plasmonic hybrid mode. Due to the inherent narrow bandwidth of the photonic resonance in periodic arrays the hybrid mode has a narrow bandwidth. Quasicrystalline structures in essence possess several periodicities which in some cases can lead to the formation of multiple hybrid modes with wider bandwidths. Finally, it will be shown that the optical resonances of the aperiodic aggregates can be further improved by optimally placing perturbing spheres within the prototiles that comprise the aperiodic arrays.