We propose a broadband infrared absorber by engineering the frequency dispersion of metamaterial surface (metasurface) to mimic an ideal absorbing sheet. With a thin layer of structured nichrome, a polarization-independent absorber with absorption larger than 97% is numerically demonstrated over a larger than one octave bandwidth. It is shown that the bandwidth enhancement is related with the transformation of the Drude model of free electron gas in metal film to the Lorentz oscillator model of a bound electron in the structured metallic surface. We believe that the concept of dispersion engineering may provide helpful guidance for the design of a broadband absorber.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OL.37.002133 | DOI Listing |
Sensors (Basel)
December 2024
Institute of Fundamental Technological Research, Polish Academy of Sciences, ul. Pawińskiego 5B, 02-106 Warsaw, Poland.
In this paper, we demonstrate that torsional surface elastic waves can propagate along the curved surface of a metamaterial elastic rod (cylinder) embedded in a conventional elastic medium. The crucial parameter of the metamaterial rod is its elastic compliance s44(1)ω, which varies as a function of frequency ω analogously to the dielectric function εω in Drude's model of metals. As a consequence, the elastic compliance s44(1)ω can take negative values s44(1)ω<0 as a function of frequency ω.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
Lattice structures are an innovative solution to increase the strength-to-weight ratio of a structure. In this study, two polymeric hybrid lattice structures-"FRB" (a heterogenous structure which is indeed a BCC structure reinforced by FCC unit cells dispersed in a way to form a chessboard pattern in each layer) and the "Multifunctional" (a homogenous structure whose unit cells are a combination of FCC and BCC unit cells where their central nodes are connected)-are proposed, fabricated via liquid crystal display 3D printing technique, and their mechanical characteristics are evaluated under quasi-static loading, experimentally and numerically. The results indicate a 15.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Fano resonance is achieved by tuning two coupled oscillators and has exceptional potential for modulating light dispersion. Here, distinct from the classical Fano resonances achieved through photonics methodologies, we introduce the Fano resonance in epsilon-near-zero (ENZ) media with novel electromagnetic properties. By adjusting the background permeability of the ENZ host, the transmission spectrum exhibits various dispersive line shapes and covers the full range of Fano parameter q morphologies, from negative to positive infinity.
View Article and Find Full Text PDFSci Rep
January 2025
Electrical Engineering Department, Kuwait University, 13060, Kuwait City, Kuwait.
Nano Lett
January 2025
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Guangzhou 510632, P. R. China.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!