Three-Dimensional Plasmonic Nanoclusters*

Recent developments in the control and manipulation of electromagnetic radiation allow for the emergence of new concepts, found only in artificially engineered nanoscale media. Assembling nanoparticles into well-defined structures is an important way to create and tailor the optical properties of materials. While displaying fascinating optical properties, nanostructures created by self-assembly or lithography have a major drawback; strong angular-dependent optical properties resulting from their two-dimensionality. Here, we present novel three-dimensional nanoclusters comprised of noble metal nanoparticles encapsulated in a polymer displaying interesting optical features in the visible (Fano resonances, optical isotropy,...). We investigate the nature of the optical properties and their dependence on cluster geometry. Such three-dimensional clusters show great promise as optical kernels for metafluids, imparting metamaterial optical properties into disordered media such as liquids, glasses, or plastics, free from the requirement of nanostructure orientation.