Use Of Metamaterials Research Articles

Prism coupling to 'designer' surface plasmons

The excitation of 'designer' surface-plasmon-like modes on periodically perforated metals is demonstrated at microwave frequencies using the classical method of prism-coupling. In addition we provide a complete formalism for accurately determining the dispersion of these surface modes. Our findings fully validate the use of metamaterials to give surface plasmon-like behavior at frequencies below the visible.

WIDE-ANGLE ABSORPTION BY THE USE OF A METAMATERIAL PLATE

The problem regarding top possible (hopefully, total) fleld suppression of a fll- amentary source placed above nonuniform impedance plane is discussed. New designs of the electromagnetic fleld absorbers and resonators are suggested which may be engineered with the use of metamaterials. 1. INTRODUCTION | ABSORPTION OF THE ENERGY OF A POINT SOURCE BY A HALF-SPACE Interest to the fleld propagation along the imperfect surface has about century-old history, the beginnings of which trace back to the Sommerfeld's solution of the classical problem for the dipole radiating above the plane with flnite conductivity. Later, as the radio broadcasting evolved, a lot of publications appeared which dealt with electromagnetic fleld propagation in the presence of an absorbing half-space with the aim to minimize the signal losses. Now certain practical needs (1) set questions about what value of impedance of a plane should be chosen to absorb the maximum portion of energy radiated by a point source (say, fllamentary current), how much the amount of the absorbed energy is and how to create such an impedance. Note, in view of the symmetry of the radiation pattern of the fllament, at the absence of the plate (in the free space) equal power ∞uxes are radiated into upper and lower half-spaces, and exactly one half of the radiated energy penetrates through the plane y = 0, see Fig. 1.

A consideration of the use of metamaterials for sensing applications: field fluctuations and ultimate performance

We analysed some peculiarities of electromagnetic metamaterials convenient for plasmon-based chemical sensing with enhanced sensitivity. Owing to the vastly extended range of possible values of refractive index, a higher degree of design freedom is enabled in comparison to conventional surface plasmon sensors. After considering some possible approaches to use metamaterials as either surface or bulk adsorbents, we analysed the ultimate performance of such sensing devices which are limited by refractive index fluctuations caused by adsorption and desorption processes. We utilized an approach based on a parallel between the adsorption–desorption mechanism and the carrier generation–recombination in semiconductors. As a special case, we considered structures for the detection of a single gas and used our approach to calculate the spectral density of refractive index fluctuations. We believe that our analysis may be of importance in different practical fields, including e.g. environmental sensing, homeland security and biosensing.

GENERALIZED SURFACE PLASMON RESONANCE SENSORS USING METAMATERIALS AND NEGATIVE INDEX MATERIALS

Optical surface plasmon resonance sensors have been known for a long time. In this paper, we discuss the use of metamaterials to construct a surface plasmon sensor which can be used at microwave frequencies. We review the conditions for the existence of surface plasmon and the use of the forward and backward surface waves. A sharp dip in the reflection coefficient occurs when the propagation constant of the incident wave along the surface is nearly equal to the propagation constant of the plasmon surface wave and may be used to probe bulk material characteristics or to determine metamaterial characteristics. Numerical examples are given to illustrate the basic characteristics.