Polarization dependent transmission through asymmetric C-shaped holes

Abstract

We report that asymmetric c-shaped holes show mode switching between single- and double-resonance frequencies in the terahertz region, when the polarization direction of the incident light is controlled. The number of resonant frequencies is attributed to fundamental shape modes such as circle-, coaxial-, and rectangular-shaped holes activated under each polarization condition. All of these resonant peaks also show a transmission of over 90% with the assistance of the periodically arranged holes. These experimental results are in close agreement with theoretical simulations.

Optical filtering properties of subwavelength Tai-chi-shaped metal hole arrays

“…13(a), we can see that a narrow band exists around wavelength of λ¼620 nm, which is in the orange wavelengths. The fullwidth at half-maximum (FWHM) is about 20 nm, which is much smaller than those mentioned in previous works [17,19,22,25,31]. This is important for potential applications in novel light emitting diode devices to obtain light with pure color.…”

“…When a figure has more symmetry axes, we view it as a higher degree of symmetry. Some structures with poor symmetry such as cross-shaped [10], X-shaped [21], C-shaped [22] and oriented elliptical [23][24][25][26] hole arrays were studied. The transmission is strongly dependent on the polarization of incident light in these structures.…”

Characteristics of multi-mode resonances in T-shape air slots

“…The resonant properties in resonators originate from cavity resonances determined by the structural parameters of apertures. [19][20][21][22] The resonances correspond to dipole resonance with linear structures or LC resonance with structures having curvature, which is usually explained by Babinet's principle, in antennas. 11,23 We therefore expect three different origins, which are usually attributed to the half-wavelength-mode cut-off frequencies in simple unit structures with different geometrical parameters, for generating the three resonance modes.…”

Teeter-totter effect of terahertz dual modes in C-shaped complementary split-ring resonators

“…In this configuration, the electric component is perpendicular to the gap of the CSRRs, while the magnetic component is perpendicular to the gap. Normally, dual resonance modes occur when the incident THz polarization is perpendicular to the gap of SRR structure-based metamaterials, 14,28 however, only one mode is observed since the net electric dipole moment is large when the incident THz polarization is parallel to the gap (as shown in Fig. S1 Supplemental Material 29 ).…”

“…To the H modes, however, the electrical energy is distributed separately into three sections, which is similar as perforated C-shape hole. 28 When the gap opens up, the electrical energy of L modes of the CSRRs gradually accumulates in the open area of the loop. In contrast, the electrical energy density of H modes gradually diminishes.…”