Electrically resonant terahertz metamaterials: Theoretical and experimental investigations

Abstract

We present a class of artificial materials that exhibit a tailored response to the electrical component of electromagnetic radiation. These electric metamaterials are investigated theoretically, computationally, and experimentally using terahertz time-domain spectroscopy. These structures display a resonant response including regions of negative permittivity ⑀ 1 ͑͒ Ͻ 0 ranging from ϳ500 GHz to 1 THz. Conventional electric media such as distributed wires are difficult to incorporate into metamaterials. In contrast, these localized structures will simplify the construction of future metamaterials, including those with negative index of refraction. As these structures generalize to three dimensions in a straightforward manner, they will significantly enhance the design and fabrication of functional terahertz devices.

Design, theory, and measurement of a polarization-insensitive absorber for terahertz imaging

“…Spatial dispersion also causes antiresonances inμ (ǫ) due to resonances inǫ (μ) [26]. Additionally, conventional electric [27,28] and magnetic [15] MMs are highly coupled when they share a center resonant frequency [29]. Typically, electric metamaterials have higher order electric resonances, and thus in general one does not necessarily have the condition that ǫ ∞ = µ ∞ , leading to a nonzero reflectivity as described above.…”

“…The ERR chosen had fourfold rotational symmetry about the propagation axis and was therefore polarization insensitive [27]. The lowerfrequency electric response used to tune the ǫ(ω) curve was driven by the LC loop in the ERR.…”

Ultra-Compact Metamaterial Absorber With Low-Permittivity Dielectric Substrate

“…1. Such two MA configurations were discussed previously [6,30], and the corresponding metamaterial units, the electric-LC (ELC) resonators, were also analyzed comparatively [31], which shows that the side-by-side split ring resonator [ Fig. 1(f)] has lower operating frequency compared to the classic one [ Fig.…”

A Metamaterial Based Microwave Absorber Composed of Coplanar Electric-Field-Coupled Resonator and Wire Array

“…We created a double-negative MTM structure by combining an ELC resonator and a wire in the same plane. When a time-varying electric field, polarized in the direction normal to the capacitor plates of the ELC, is incident upon the MTM structure, an electric response is provided by the ELC resonator [21]. In the case where a magnetic field, polarized normal to the loops of the ELC resonator, is incident upon the MTM structure, anti-parallel surface currents are induced in both the wire and one metallic loop pattern of the ELC resonator, resulting in a magnetic response.…”