Dual-band asymmetric transmission of linear polarization in bilayered chiral metamaterial

Abstract

A bilayered chiral metamaterial is proposed and demonstrated to exhibit dual-band asymmetric transmission of linearly polarized electromagnetic waves in two opposite directions. Simulated and measured results show that the bilayered chiral metamaterial can achieve cross-polarization conversion with an efficiency of over 90% for both y- and x-polarized waves. The proposed metasurface can be regarded as an ultrathin polarization-controlled switch that is easily switched on/off by changing a linearly polarized wave to its orthogonal component.

Efficient Dual-Band Asymmetric Transmission of Linearly Polarized Wave Using a Chiral Metamaterial

“…However, in the earlier proposed CMM, the AT effect is usually in a narrow band which separates them from the practical applications. More recently, great efforts have been devoted to achieve broadband (or dual-band) as well as high efficiency AT effect for linearly polarized wave [18][19][20][21][22][23]. Shi et al [18] proposed that a bi-layered CMM consisting of double I-shaped resonators realized dual-band AT for linearly polarized wave.…”

“…More recently, great efforts have been devoted to achieve broadband (or dual-band) as well as high efficiency AT effect for linearly polarized wave [18][19][20][21][22][23]. Shi et al [18] proposed that a bi-layered CMM consisting of double I-shaped resonators realized dual-band AT for linearly polarized wave. Based on a Fabry-Perot-like cavity, a three-layered MM has been proposed to obtain a broadband AT effect only for a specific linearly polarized wave at microwave frequencies [21].…”

Using dual-band asymmetric transmission effect of 2D metamaterial to manipulate linear polarization state of electromagnetic waves

“…As suggested in Ref. 42, the induced magnetic field may couple with the incident electric field, which can give rise to polarization conversion. The colored arrows represent the directions of currents and induced fields, but they don't represent the magnitudes of induced magnetic fields.…”

“…According to Ref. 42, H 2 and H 3 are orthogonal to the incident electric field E so that they never contribute to the polarization transformation since they cannot excite cross coupling between the induced magnetic field and the incident electric field E. While the induced magnetic fields H 1 and H 4 are parallel to the incident electric field E, the cross coupling between the electric and magnetic fields results in a cross-polarization transmission. As a result, the x-polarization state is transformed into the y-polarization one at 5.53 GHz.…”

“…28,32,33 Most recently, a few planar chiral structures with AT properties have been proposed to realize both circular and linear AT phenomena, such as crossed resonant structures, planar split-circle structures, corrugated elliptical gratings and stacked split-ring resonators. [34][35][36][37][38][39][40][41][42] These studies, however, were limited by the structures or the high dielectric loss, and pitfalls that the transforming band was single and the conversion efficiency was restrained. Therefore simple structure, high conversion efficiency and multi-band operations of manipulating linear polarization by AT effect are still highly desirable.…”