Showing papers on "Metamaterial absorber published in 2006"

Spectroscopy of metamaterials from infrared to optical frequencies

Abstract: We review both the theoretical electromagnetic response and the spectroscopic measurements of metamaterials. To critically examine published results for metamaterial structures operating in the range from terahertz to optical frequencies, we focus on protocols allowing one to extract the optical constants from experimental observables. We discuss the complexity of this task when applied to metamaterials exhibiting electric, magnetic, and magneto-optical response. The general theory of the electromagnetic response of such systems is presented and methods are described. Finally, we briefly overview possible solutions for implementing metamaterials with tunable resonant behavior. © 2006 Optical Society of America OCIS codes: 160.3820, 300.6270, 120.2130, 160.4760.

Ultrathin, metamaterial-based laser cavities

Abstract: The negative-index property of double-negative metamaterials and the effective matching property of single-negative metamaterials are used to achieve ultrathin laser cavities. Open and partially closed cavities are considered. Resonant enhancement of the output fields is demonstrated in both cases with a variety of metamaterial combinations.

Metamaterial-based source and scattering enhancements: from microwave to optical frequencies

Abstract: A brief review of metamaterial applications to source and scattering problems in the microwave and optical frequency regimes is given. Issues associated with modelling these systems are discussed. Electrically small radiating and scattering systems are emphasized. Single negative, double negative, and zero-index versions of these metamaterial-based systems are introduced that provide a means to manipulate their efficiency, bandwidth, and directivity characteristics.

Effect of Substrate Dielectric Properties and Tunable Metamaterials

Abstract: The effect of substrate dielectric properties on the overall performance of split ring resonator (SRR) metamaterials was investigated. Results of a finite element simulation show notable differences of metamaterial properties with different substrate dielectric properties. The resonance frequency change can be used to roughly characterize the effect of the change of the substrate dielectric property. Since the electromagnetic properties of a metamaterial vary largely at the frequencies around the resonance frequency, the metamaterial properties can be effectively tailored by adjusting the substrate properties. This means the substrate provides an additional dimension of flexibility for the design of the metamaterials. On the other hand, considering the tunability of the metamaterials, which is required in many applications, we notice it is a very effective way to achieve tunable metamaterials by tuning the properties of the substrate. Although the change of the geometry or the electromagnetic properties of the metallized structures will result in metamaterials with different properties, it should be noted that the tuning of the size or the metal properties is more difficult and very limited once the geometry is determined. The substrate properties, however, can be tuned relatively easily by, for example, temperature, stress, bias voltages, bias currents, etc. How to tune the substrates is not within the coverage of this paper, but our simulation results show a tunable metamaterial can be implemented by fixed metallized structures on a tunable substrate

EM modeling and design of electrically thin laminated absorbers

Abstract: The paper describes an equivalent circuit approach for the analysis and the electromagnetic design of innovative thin absorbers. The use of thin bilayers of metamaterials as spacer in dielectric Salisbury screen is discussed. It is demonstrated that narrow-band thin absorbers can be obtained using both positive and negative materials, whereas broad-band thin absorbing screen can be realized only with bilayer of epsilon-negative and mu-negative materials.