Figure 1

Dextral ($\mathbf{D}$, right-handed) and sinistral ($\mathbf{S}$, left-handed) enantiomeric helicoidal bilayered structures constructed from planar metal rosettes separated by a dielectric slab of thickness $d$. $L$ is the end-to-end length of the rosette’s strip and $W$ is its width. The rosettes forming the enantiomeric structures are mutually twisted around the axis of fourfold symmetry on angles $-\phi$ and $\phi$, respectively.Reuse & Permissions

Figure 2

Electromagnetic properties of the bilayered sinistral chiral structure with mutual twist $\phi =15°$. Frequency dependencies of: (a) circular dichroism, $\Delta$ (black line) and circular differential phase delay, $\delta$ (gray line); (b) transmission losses for left circularly polarized wave (black line) and right circularly polarized wave (gray line); (c) the phase delay for left circularly polarized wave (black line) and right circularly polarized wave (gray line). The shaded area in (c) represents a frequency range where the phase velocity $v_p$ and group velocity $v_g$ have opposite signs for right circular polarization, which could be a signature of negative refraction.Reuse & Permissions

Figure 3

Frequency dependencies of polarization azimuth rotation $\theta$ (left column) and ellipticity, in terms of the ellipticity angle $\eta$ (right column) that a linearly polarized wave would acquire upon transmission through a sinistral bilayered chiral structure for various twist angles $\phi$. Vertical scale is shown in the right bottom corners. Dotted line at $\phi =15°$ shows the frequency dispersion of the effect as predicted by the Born-Kuhn model.Reuse & Permissions