High absorption and a tunable broadband absorption based on the fractal Technology of Infrared Metamaterial Broadband Absorber

Review of Broadband Metamaterial Absorbers: From Principles, Design Strategies, and Tunable Properties to Functional Applications

“…According to the number of subresonators in the top patterned layer or surface structure of MAs, there are three common planer design strategies, which are 1) single resonator design approach, [271,[339][340][341][342][343] 2) combined design strategy of multiple sub-resonators, [272,344,345] and 3) fractal design approach. [273,[346][347][348][349] Single resonator design approach means that the unit cell (UC) of the surface structure of BMAs contains only one (or single) patterned resonator. The combined design strategy of multiple sub-resonators indicates that the surface structure of BMAs possesses at least two or more sub-resonators.…”

“…Due to the self-similarity of the fractal structures, they typically show multiple resonance modes, and with the increase of fractal orders, the number of exciting resonance modes tends to increase; the combining effect of these induced modes in fractal resonators could produce broadband absorption, and thus the application of fractal designs to BMAs often results in excellent broadband absorption performance. [146,273,[346][347][348][349] More importantly, the concept of fractal designs for broadband absorption can also greatly enrich and expand the design ideas of BMAs. Therefore, as an important design branch of BMAs, the fractal design method has been continuously reported.…”

“…Gu et al designed a planar isotropic BMA using densely arranged hexagonal fractal metallic dendritic cells of different sizes, [346] to achieve dual broadband absorption in the X-band as well as the S-band. A cross-fractal BMA for the MIR region was proposed, [347] yielding a broadband absorption of 2.86 µm when the fractal order equals 3. However, this BMA has the disadvantage of a complex structural design and complicated preparation steps.…”

Metamaterial ultra-wideband solar absorbers based on a multi-layer structure with cross etching

“…In recent years, more and more researchers have focused on achieving broadband absorption. [5][6][7][8] In 2012, Cui et al 9 designed an absorber that achieved more than 95% absorption in the infrared band. In 2013, Liang et al 10 designed a metamaterial absorber with a two-dimensional pyramid structure that achieved near-perfect absorption in the band of 1000-1400 nm.…”

Near Perfect Absorber for Long-Wave Infrared Based on Localized Surface Plasmon Resonance

“…T. Xie’s and Y. Liang’s designs adopted two more complex surface metal structures. The former achieved more than 90% absorption peaks in the two atmospheric windows, respectively [ 20 ], and the latter achieved 94.3% of the average absorption in the band of 12.3–32.0 μm [ 21 ]. Meta-surface structure arrays can precisely control the absorption spectrum range by adjusting the size and morphology of surface metal structures, which are suitable for different application scenarios.…”