13 research outputs found
Surface waves in three-dimensional electromagnetic composites and their effect on homogenization
Reflection and transmission of electromagnetic waves at the boundaries of periodic composites (electromagnetic/optical metamaterials) depends in general on both bulk and surface waves. We investigate the interplay of these two contributions using three-dimensional full-wave numerical simulations and a recently developed non-asymptotic homoge-nization theory. © 2013 Optical Society of America.postprin
Fluctuations and scaling of inverse participation ratios in random binary resonant composites
We study the statistics of local field distribution solved by the
Green's-function formalism (GFF) [Y. Gu et al., Phys. Rev. B {\bf 59} 12847
(1999)] in the disordered binary resonant composites. For a percolating
network, the inverse participation ratios (IPR) with are illustrated, as
well as the typical local field distributions of localized and extended states.
Numerical calculations indicate that for a definite fraction the
distribution function of IPR has a scale invariant form. It is also shown
the scaling behavior of the ensemble averaged described by the
fractal dimension . To relate the eigenvectors correlations to resonance
level statistics, the axial symmetry between and the spectral
compressibility is obtained.Comment: 7 pages, 6 figures, accepted by Physical Review
Quantum interference in nanofractals and its optical manifestation
We consider quantum interferences of ballistic electrons propagating inside
fractal structures with nanometric size of their arms. We use a scaling
argument to calculate the density of states of free electrons confined in a
simple model fractal. We show how the fractal dimension governs the density of
states and optical properties of fractal structures in the RF-IR region. We
discuss the effect of disorder on the density of states along with the
possibility of experimental observation.Comment: 19 pages, 6 figure
Processes in resonant domains of metal nanoparticle aggregates and optical nonlinearity of aggregates in pulsed laser fields
Toward superlensing with metal-dielectric composites and multilayers
We report on the fabrication of two types of adjustable, near-field superlens designs: metal-dielectric composites and metal-dielectric multilayer films. We fabricated a variety of films with different materials, thicknesses and compositions. These samples were characterized physically and optically to determine their film composition, quality, and optical responses. Our results on metal-dielectric composites indicate that although the real part of the effective permittivity generally follows effective medium theory predictions, the imaginary part does not and substantially higher losses are observed. Going forward, it appears that multilayer metal-dielectric designs are more suitable for sub-diffraction imaging applications because they could provide both tunability and low loss