Wide-angle, polarization-independent and dual-band infrared perfect absorber based on L-shaped metamaterial

Abstract

We propose a wide-angle, polarization-independent and dual-band infrared perfect metamaterial absorber made of double L-shaped gold patches on a dielectric spacer and opaque gold ground layer. Numerical and experimental results demonstrate that the absorber has two near-unity absorption peaks, which are result from magnetic polariton modes generated at two different resonant wavelengths. In addition, the proposed structure also shows good absorption stability in a wide range of incident anglesθfor both TE and TM incidences at azimuthal angle φ = 0°. Moreover, we demonstrate that such structure has good absorption stability for a wide range of azimuthal angles due to the excitation of perpendicular magnetic polariton modes within the asymmetric double L-shaped structure. Such structure will assist in designing magnetic polaritons absorbing element for infrared spectroscopy and imaging.

Tunable graphene-based mid-infrared plasmonic wide-angle narrowband perfect absorber

“…Simultaneously, the transmittance is eliminated via maximizing the metamaterial losses, for example, by introducing another metallic plate acting as the substrate13. So far, based on this mechanism, metamaterial near-unity absorbers with electrical resonators including metallic disks14, strips1516, crosses10, and L-shaped structures17 have been designed and investigated comprehensively. By combining multiple resonators with different sizes together to form a super unit cell, the multi-channel or broadband perfect absorbers have also been achieved18192021.…”

Infrared Perfect Ultra-narrow Band Absorber as Plasmonic Sensor

“…2b, the high absorption is caused by the magnetic resonance resulting from LSPR. The equivalent LC circuit model can be used to explain the characteristics of the reflection resonant dip in this work [42][43][44][45][46]. Here, the mutual inductance L m of the gold nanobars and gold film can be represented by L m = 0.5 μ 0 wt 2 , where μ 0 is the permeability of surrounding environment [44][45][46].…”

A reflective-backing-free metamaterial absorber with broadband response

“…[6][7][8][9] However, these absorbers are usually backed by a metallic plate. [10][11][12][13] The usual function of metallic backing is to provide electric boundary condition for incident plane wave, and enables to create magnetic resonance. Besides, it is used to avoid power transmission on the other side of the absorber.…”