Dual-Band Terahertz Chiral Metamaterial With Giant Optical Activity and Negative Refractive Index Based on Cross-Wire Strucure

Abstract

Abstract-In this paper, a dualband chiral metamaterial (CMM) based on cross-wire structure is proposed and studied numerically. It exhibits dual-band giant optical activity and negative refractive index in terahertz region. The surface current distributions are calculated to explain original physics. The further numerical results show that the effective frequency bands of the CMMs can be independent adjusted easily by changing the structure geometrical parameter. The designed dual-band terahertz CMMs offer flexibility in the investigation of novel terahertz device application.

Chiral All-Dielectric Metasurface Based on Elliptic Resonators with Circular Dichroism Behavior

“…On the other hand, chiral metamaterials [17,18] have attracted much attention due to their interesting properties such as optical activity [19,20], circular dichroism [21], and negative refractive index [20]. In these artificial media, the optical and circular dichroism properties are many orders of magnitude higher than those in natural chiral materials, whereas negative refractive index property can be achieved without combination of negative permeability and negative permittivity.…”

A Full-Dielectric Chiral Material Based on a Honeycomb Structure

“…Consequences of this effect are a rotation of the polarization angle when the travelling wave is linearly polarized (optical/electromagnetic activity), as well as a polarization change from lineal to elliptical and, eventually, circular [5]. Furthermore, in 2004, it was predicted that materials with strong electromagnetic activity can also possess a negative refractive index [7], and since then, several chiral metamaterial (CM) designs have been proposed and probed to produce such a negative refractive index [8,9].…”

Characterization and performance analysis of a chiral-metamaterial channel with Giant Optical Activity for terahertz communications

“…Advanced physical layer solutions are required, able to capture the specific 8 and inherent features of the THz frequency bands. Indeed, traditional channel 9 models for lower frequency bands cannot be adopted for THz communication. 10 Some new channel models have been presented for THz frequency bands [2, 11 3, 4, 5, 6], where some of the specific characteristics of this frequency band, such 12 as the high molecular absorption and the spreading loss, are taken into consider- 13 ation and analyzed.…”

“…Examples of natural chiral materials are the sugar 8 molecules (sucrose) or the cholesteric liquid crystals. Artificial chiral materials, 9 e.g., sculptured thin films [8], can be obtained by doping a natural dielectric with 10 an amount of metallic/dielectric impurities each working as a couple of interacting 11 electro-magnetic dipoles. These impurities generate the handedness experimen- 12 tal evidence that prevents the superimposition of the molecular structure over a 13 reverse copy of itself.…”

“…Materials with this specific feature are said to exhibit a Giant Optical Activity 19 (GOA). In particular media such as the chiral complex materials where a GOA 20 takes place, the relative chirality parameter is complex and frequency-dependent, 21 showing multiple peaks at specific resonance frequencies [9]. 22 GOA material affected by chirality effects is generally called as chiral-metamaterial [10], 23 due to the effect that the real part of relative electric permittivity and magnetic 24 permeability of the material shows negative values, and are frequency-dependent.…”