73 research outputs found
Three-dimensional isotropic perfect lens based on LC-loaded transmission lines
An isotropic three-dimentional perfect lens based on cubic meshes of
interconnected transmission lines and bulk loads is proposed. The lens is
formed by a slab of a loaded mesh placed in between two similar unloaded
meshes. The dispersion equations and the characteristic impedances of the
eigenwaves in the meshes are derived analytically, with an emphasis on
generality. This allows designing of transmission-line meshes with desired
dispersion properties. The required backward-wave mode of operation in the lens
is realized with simple inductive and capacitive loads. An analytical
expression for the transmission through the lens is derived and the
amplification of evanescent waves is demonstrated. Factors that influence
enhancement of evanescent waves in the lens are studied and the corresponding
design criteria are established. A possible realization of the structure is
outlined.Comment: 22 pages, 15 figure
Non-local permittivity from a quasi-static model for a class of wire media
A simple quasi-static model applicable to a wide class of wire media is
developed that explains strong non-locality in the dielectric response of wire
media in clear physical terms of effective inductance and capacitance per unit
length of a wire. The model is checked against known solutions and found to be
in excellent agreement with the results obtained by much more sophisticated
analytical and numerical methods. Special attention is given to suppression of
the spatial dispersion effects in wire media.Comment: 22 pagees, 4 figure
Modeling of Isotropic Backward-Wave Materials Composed of Resonant Spheres
A possibility to realize isotropic artificial backward-wave materials is
theoretically analyzed. An improved mixing rule for the effective permittivity
of a composite material consisting of two sets of resonant dielectric spheres
in a homogeneous background is presented. The equations are validated using the
Mie theory and numerical simulations. The effect of a statistical distribution
of sphere sizes on the increasing of losses in the operating frequency band is
discussed and some examples are shown.Comment: 15 pages, 7 figure
Perfect lensing with phase conjugating surfaces: Towards practical realization
It is theoretically known that a pair of phase conjugating surfaces can
function as a perfect lens, focusing propagating waves and enhancing evanescent
waves. However, the known experimental approaches based on thin sheets of
nonlinear materials cannot fully realize the required phase conjugation
boundary condition. In this paper we show that the ideal phase conjugating
surface is in principle physically realizable and investigate the necessary
properties of nonlinear and nonreciprocal particles which can be used to build
a perfect lens system. The physical principle of the lens operation is
discussed in detail and directions of possible experimental realizations are
outlined.Comment: 16 pages, 5 figure
Symmetry and reciprocity constraints on diffraction by gratings of quasi-planar particles
Symmetry and reciprocity constraints on polarization state of the field
diffracted by gratings of quasi-planar particles are considered. It is shown
that the optical activity effects observed recently in arrays of quasi-planar
plasmonic particles on a dielectric substrate are due to the reflection of the
field at the air-dielectric slab interface and are proportional to this
reflection coefficient.Comment: 11 pages, 3 figures, 12 references; minor corrections for better
appearanc
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