Dual-Band Terahertz Perfect Absorber Based on Metal Micro-Nano Structure

Abstract

We propose a sub-wavelength range-based dual-band tunable ideal terahertz metamaterial perfect absorber. The absorber structure consists of three main layers, with the absorber layer consisting of a metal I-shaped structure. By simulating the incident wave absorbance of the structure, we found that the structure has more than 99% absorption peaks in both bands. In addition, we have investigated the relationship between structural absorbance and the structural geometrical parameters. We have studied the relationship between the thickness of the metal absorber layer hb and the absorbance of the metamaterial structure in the 4–14 THz band. Secondly, we have studied the relationship between the thickness of the SiO2 dielectric layer and structural absorbance. Afterwards, we have studied the relationship between the incident angle of the incident electromagnetic wave and structural absorbance. Finally, we have studied the relationship between the length of the metal structure and structural absorbance. The structure can be effectively used for detectors, thermal emitters, terahertz imaging and detection.

Polarization-Angle-Insensitive Dual-Band Perfect Metamaterial Absorbers in the Visible Region: A Theoretical Study

“…where µ 0 and ε 0 denote the free-space permeability and permittivity, respectively, and µ and ε denote the permeability and permittivity of the absorbing material, respectively [38][39][40]. Perfect absorption can be achieved when the reflectivity of the structure reduces to zero.…”

“…To achieve perfect absorption, it is crucial to ensure that the equivalent impedance of the structure equals 1. Since metals have negative permittivity at low frequencies, adjusting metal parameters becomes necessary to control their permittivity [40]. Based on Equations ( 1)-( 3), when the surface impedance of a designed metamaterial structure matches that of air impedance (Z = Z 0 ), the reflection of the metamaterial structure becomes zero (R = 0).…”

“…To achieve perfect absorption, it is crucial to ensure that the equivalent impedance of the structure equals 1. Since metals have negative permittivity at low frequencies, adjusting metal parameters becomes necessary to control their permittivity [40].…”

Dielectric Cavity-Insulator-Metal (DCIM) Metamaterial Absorber in Visible Range

“…Enhanced bio/chemical sensing [1,2], energy harvesting [3], and refractive index sensing [4] is a concise list of application examples showing the great potential and value of MM absorbers. Considering the variant application aspects, for example, working frequency [5][6][7], polarization sensitivity [8], bandwidth [9,10], and thermal control [11,12], the configuration of MMs and the material selection can be different. Metal-insulator-metal MM (MIM-MM) is the most studied configuration.…”

Metamaterial Perfect Absorbers for Controlling Bandwidth: Single-Peak/Multiple-Peaks/Tailored-Band/Broadband

“…These structures are lightweight and highly flexible, making them easily integrated into existing electronic systems and devices [22,23]. Additionally, the fabrication process for metamaterial absorbers is highly versatile, allowing us to produce structures with varying shapes, sizes and properties [24][25][26][27]. As a result, these absorbers can be tailored to suit the specific application requirements [28].…”