Publications by Year: 2009

2009
Stefanou N, Gantzounis G, Tserkezis C. Multiple-scattering calculations for plasmonic nanostructures. International Journal of Nanotechnology. 2009;6(1-2):137-163.Abstract
After a brief description of the multiple-scattering method for photonic crystals, we present some results obtained by this method, relating to various types of plasmonic nanostructures in one, two and three dimensions: cavity plasmon waveguides, systems of metallic particles, and arrays of metallic shells. We analyse the optical response of these structures and emphasise some interesting aspects of the underlying physics.
Tserkezis C, Stefanou N, Gantzounis G, Papanikolaou N. Negative effective permeability of multilayers of ordered arrays of metal-dielectric nanosandwiches. Proceedings of SPIE. 2009;7353:735305 (8 pages).Abstract
We present a thorough theoretical study of the optical properties of periodic structures built of silver and silica nanodisks in a sandwich-like configuration, by means of full electrodynamic calculations using the extended layer-multiple-scattering method. The strong coupling of the metallic nanoparticles and the resulting plasmon hybridization lead to collective electric and magnetic resonant modes, which can be tuned by changing the structural parameters, such as nanoparticle size and lattice constant. We analyze the response of single- and multi-layer architectures of ordered arrays of such nanosandwiches on a dielectric substrate to externally incident light and evaluate the corresponding effective permittivity and permeability functions. Our results reveal the existence of optical magnetism, with a strong negative effective permeability over a tunable spectral range at near-infrared and visible frequencies. We introduce the complex photonic band structure as a tool in the study of three-dimensional metamaterials and establish additional criteria for the validity of their effective-medium description. Our work demonstrates the efficiency of the recently developed extended layer-multiple-scattering method in the study of metamaterials of composite metal-dielectric particles of arbitrary shape.
Tserkezis C, Papanikolaou N, Almpanis E, Stefanou N. Tailoring plasmons with metallic nanorod arrays. Physical Review B. 2009;80(12):125124 (9 pages).Abstract
We report a thorough theoretical study of the optical response of two- and three-dimensional periodic assemblies of metallic nanorods by means of full-electrodynamic calculations using the extended layer-multiple-scattering method. We show that these systems support various types of resonant- and bound-collective plasmon modes, which are tunable over a broad spectral range, and provide a consistent interpretation of the underlying physics. In particular, we reveal the existence of slab plasmon modes with zero group velocity, which can cause evanescent-wave enhancement and enable subwavelength imaging. We discuss extinction spectra of single-layer and multilayer slabs of nanorods in conjunction with relevant complex band-structure diagrams and present a rigorous analysis of the results using group theory. Moreover, we explain some peculiar spectral features which are due to the existence of surface resonances. These can modify the optical response of the system in a controllable manner by using a supporting substrate.