Infrared perfect absorber based on nanowire metamaterial cavities

Abstract

An infrared perfect absorber based on a gold nanowire metamaterial cavities array on a gold ground plane is designed. The metamaterial made of gold nanowires embedded in an alumina host exhibits an effective permittivity with strong anisotropy, which supports cavity resonant modes of both electric dipole and magnetic dipole. The impedance of the cavity modes matches the incident plane wave in free space, leading to nearly perfect light absorption. The incident optical energy is efficiently converted into heat so that the local temperature of the absorber will increase. Results show that the designed absorber is polarization-insensitive and nearly omnidirectional for the incident angle.

Multifunctional Material Structures Based on Laser-Etched Carbon Nanotube Arrays

“…Further analysis of the effect of patterning at higher frequency is under progress. Figure 7 shows a prediction of resonance absorption in the THz range, following the approach adapted from [13] for patterns of nanowires. The 50 µm × 50 µm squared CNT plot has a spatial anisotropy of its macroscopic permittivity expressed as:…”

Polypropylene Carbon Nanotubes Nanocomposites: Combined Influence of Block Copolymer Compatibilizer and Melt Annealing on Electrical Properties

“…This leads to a renewed interest for electromagnetic absorber materials, which simultaneously reduce the reflection and transmission of the signal. Besides metamaterials designed to absorb specific frequencies by resonance [8], composite-based materials containing conductive inclusions, for example, metal powders, ferrites, carbon, and conjugated polymers, have already been proposed as electromagnetic 2 Journal of Nanomaterials (EM) absorbers [9][10][11][12][13][14][15][16][17][18][19]. Again, well dispersed polymer-CNT nanocomposites (possibly foamed, see [20,21]) are attractive for broadband absorption in the GHz frequency range because the high aspect ratio of CNT allows reaching sufficient conductivity at low filler content and hence the elusive combination of high conductivity and low dielectric constant, which is essential for effective absorption [5,[21][22][23][24].…”

Engineering Hybrid Guided Modes in Subwavelength Uniaxial Metamaterial Waveguides

“…Metamaterial waveguides present a new platform for guiding and manipulating electromagnetic waves. This is because that artificially engineered metamaterials have been exhibiting many novel electromagnetic properties such as negative refraction, self-induced torque, spatial filtering, subwavelength imaging, no diffraction transmission, and so on [8][9][10][11][12][13]. These electromagnetic properties cannot occur in natural materials.…”