Transmission Losses in Left-handed Materials

We present finite-differences time- domain calculations of the effective permitivity of a periodic array of Cu strip wires that are an ingredient needed in metamaterials for obtaining left-handed materials. We use the Cu frequency dependent permitivity. The result is critically dependent of the wire thickness. In particular for the wires of 0.003cm thickness used in metamaterials experiments the imaginary part of the effective permitivity dominates over the real part, which i...

The accuracy of finite-difference time-domain (FDTD) modelling of left-handed metamaterials (LHMs) is dramatically improved by using an averaging technique along the boundaries of LHM slabs. The material frequency dispersion of LHMs is taken into account using auxiliary differential equation (ADE) based dispersive FDTD methods. The dispersive FDTD method with averaged permittivity along the material boundaries is implemented for a two-dimensional (2-D) transverse electric (TE...

We report analytical calculations for the propagation of electromagnetic radiation through an inhomogeneous layer whose refractive index varies in one dimension situated between bulk right- and left-handed media. Significant field localization is generated in the layer that is caused by the coherent superposition of evanescent waves. The strength of the field localization and the transmission properties of the layer are investigated as a function of the layer width, losses an...

Effect of anisotropy in the physical tensor description of the negative index of refraction material (left-handed material, LHM) acting as a substrate is found on the electromagnetic field distributions. Field distributions are provided in the GHz region in the cross-section of the uniform microstrip guided wave structure. It is found from ab initio Green's function calculations that modifying the tensor can allow control because the wave changes volumetrically, or switches f...

A [pi]-shaped metallic metamaterial (geometrically, a combination medium of C-shaped resonators and continuous wires) is proposed to numerically investigate its transmission band near the resonant frequency, where otherwise it should be a negative-permeability (or negative-permittivity) stop band if either the C-shaped or continuous-wire constituent is separately considered. However, in contrast to the left-handed materials (LHMs)composed of split-ring resonators and wires as...

We study the frequency dependence of the effective electromagnetic parameters of left-handed and related meta-materials of the split ring resonator and wire type. We show that the reduced translational symmetry (periodic structure) inherent to these meta-materials influences their effective electromagnetic response. To anticipate this periodicity, we formulate a periodic effective medium model which enables us to distinguish the resonant behavior of electromagnetic parameters...

We investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel dielectric cylinders embedded a uniform medium. The transmission of electromagnetic waves through prism structures are calculated by the standard multiple scattering theory. The results demonstrate that in certain frequency regimes and when the propagation inside the scattering media is not considered, the transmission behavior mimics that expected for a left-handed materia...

We consider questions about the much discussed "perfect lenses" made by left handed materials. The transmission and reflection from a slab of left handed materials are investigated and the coefficients are obtained by the standard transfer matrix method. Possible limitations on such superlenses are explored. It is shown that the quality of the lenses can be significantly affected by the absorption that is necessarily present in the materials.

In this work the analytical model explaining the losses in the known two-phase lattice of D. Smith, S. Schultz and R. Shelby representing a uniaxial variant of left-handed medium (LHM) at microwaves is presented. The role of electromagnetic interaction between split-ring resonators (SRRs) and straight wires leading to the dramatic increase of ohmic losses in SRRs within the band when the meta-material becomes a LHM is clarified. {This paper explains why in this structure, r...

An analytical theory is developed for parametric interactions in metamaterial multilayer structures with simultaneous nonlinear electronic and magnetic responses and with near-zero refractive-index. We demonstrate theoretically that electromagnetic fields of certain frequencies can be parametrically shielded by a nonlinear left-handed material slab, where the permittivity and permeability are both negative. The skin depth is tunable, and even in the absence of material absorp...