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Metamaterial absorber
From Wikipedia, the free encyclopedia
A metamaterial absorber is a type of metamaterial intended to efficiently absorb
electromagnetic radiation such as light. Furthermore, metamaterials are an advance in
materials science. Hence, those metamaterials that are designed to be absorbers offer
benefits over conventional absorbers such as further miniaturization, wider
adaptability, and increased effectiveness. Intended applications for the metamaterial
absorber include emitters, sensors, spatial light modulators, infrared camouflage,
wireless communication, and use in solar photovoltaics and thermophotovoltaics.
In addition, the advent of metamaterial absorbers enable researchers to further
understand the theory of metamaterials which is derived from classical
electromagnetic wave theory. This leads to understanding the material's capabilities
and reasons for current limitations.[1]
Contents
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1 Metamaterials
2 Absorbers
3 About metamaterial absorbers
4 See also
5 References
6 Further reading
7 Links to images
Metamaterials
Interest in metamaterials is a result of their flexibility when interacting with and
controlling electromagnetic radiation such as light. These are optical materials that
can function in a manner similar to glass or prisms. However, these materials extend
the capability to control the electromagnetic radiation that flows through them. Also
the manner of control is different and new. With conventional materials the way to
alter them is to add a chemical or material such as traces of lead added to glass. In
contrast, it is the spacing and shape of a given metamaterial's components that define
its use and the way it controls electromagnetic radiation. Unlike most conventional
materials, researchers in this field can physically control electromagnetic radiation by
altering the geometry of the material's components. Also, metamaterials have
successfully interacted in electromagnetic bands across the spectrum from radio
frequencies, to microwave, terahertz, across the infrared spectrum and almost to
visible wavelengths.[1]
Absorbers
"An electromagnetic absorber neither reflects nor transmits the incident radiation.
Therefore, the power of the impinging wave is mostly absorbed in the absorber
materials. The performance of an absorber depends on its thickness and morphology,
and also the materials used to fabricate it." [2]
For example, metamaterials can be used to improve absorption in both solar
photovoltaic[3][4] and thermo-photovoltaic[5][6] applications.
"A near unity absorber is a device in which all incident radiation is absorbed at the
operating frequency–transmissivity, reflectivity, scattering and all other light
propagation channels are disabled. Electromagnetic (EM) wave absorbers can be
categorized into two types: resonant absorbers and broadband absorbers.[7]
About metamaterial absorbers
A metamaterial absorber utilizes the effective medium design of metamterials and the
loss components of permittivity and magnetic permeability to create a material that
has a high ratio of electromagnetic radiation absorption. Loss is noted in applications
of negative refractive index (photonic metamaterials, antenna systems metamaterials)
or transformation optics (metamaterial cloaking, celestial mechanics), but is typically
undesired in these applications.[1][8]
Complex permittivity and permeability are derived from metamaterials using the
effective medium approach. As effective media, metamaterials can be characterized
with complex ε(w) = ε1 + iε2 for effective permittivity and µ(w) = µ1 + i µ2 for
effective permeability. Complex values of permittivity and permeability typically
correspond to attenuation in a medium. Most of the work in metamaterials is focused
on the real parts of these parameters, which relate to wave propagation rather than
attenuation. The loss (imaginary) components are small in comparison to the real
parts and are often neglected in such cases.
However, the loss terms (ε2 and µ2) can also be engineered to create high attenuation
and correspondingly large absorption. By independently manipulating resonances in ε
and µ it is possible to absorb both the incident electric and magnetic field.
Additionally, a metamaterial can be impedance-matched to free space by engineering
its permittivity and permeability, minimizing reflectivity. Thus, it becomes a highly
capable absorber.[1][8]
This approach can be used to create thin absorbers. Typical conventional absorbers
are thick compared to wavelengths of interest,[9] which is a problem in many
applications. Since metamaterials are characterized based on their subwavelength
nature, they can be used to create effective yet thin absorbers. This is not limited to
electromagnetic absorption either.[9]
See also
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Negative index
metamaterials
History of
metamaterials
Metamaterial
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Plasmonic metamaterials Metamaterials
Superlens
scientists
Terahertz metamaterials
Transformation optics
 Richard W.
Ziolkowski
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cloaking
Photonic
metamaterials
Metamaterial
Metamaterial
antennas
Nonlinear
metamaterials
Photonic crystal
Seismic
metamaterials
Split-ring resonator
Acoustic
metamaterials
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Theories of cloaking
Academic journals
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Metamaterials (journal)
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John Pendry
David R. Smith
Nader Engheta
Ulf Leonhardt
Vladimir
Shalaev
Metamaterials books
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Metamaterials Handbook
Metamaterials: Physics
and Engineering
Explorations
References
1. Landy, N. I. et al. (2008-05-21). "Perfect Metamaterial Absorber". Phys. Rev.
Lett 100 (20): 207402 (2008) [4 pages]. arXiv:0803.1670.
Bibcode:2008PhRvL.100t7402L. doi:10.1103/PhysRevLett.100.207402.
PMID 18518577. Retrieved 2010-01-22.
2. Alici, Kamil Boratay; Bilotti, Filiberto; Vegni, Lucio; Ozbay, Ekmel (2010).
"Experimental verification of metamaterial based subwavelength microwave
absorbers" (Free PDF download). Journal of Applied Physics 108 (8): 083113.
Bibcode:2010JAP...108h3113A. doi:10.1063/1.3493736.
3. A. Vora, J. Gwamuri, N. Pala, A. Kulkarni, J.M. Pearce, and D. Ö. Güney,
"Exchanging ohmic losses in metamaterial absorbers with useful optical
absorption for photovoltaics," Sci. Rep. 4, 4901 (2014).
doi:10.1038/srep04901 arxiv preprint
4. Wang, Y., Sun, T., Paudel, T., Zhang, Y., Ren, Z., & Kempa, K. (2011).
Metamaterial-plasmonic absorber structure for high efficiency amorphous
silicon solar cells. Nano letters, 12(1), 440-445.
5. Wu, C., Neuner III, B., John, J., Milder, A., Zollars, B., Savoy, S., & Shvets,
G. (2012). Metamaterial-based integrated plasmonic absorber/emitter for solar
thermo-photovoltaic systems. Journal of Optics, 14(2), 024005.
6. Simovski, Constantin, Stanislav Maslovski, Igor Nefedov, and Sergei
Tretyakov. "Optimization of radiative heat transfer in hyperbolic
metamaterials for thermophotovoltaic applications." Optics express 21, no. 12
(2013): 14988-15013.
7. Watts, Claire M.; Liu, Xianliang; Padilla, Willie J. (2012). "Metamaterial
Electromagnetic Wave Absorbers" (Free PDF download available). Advanced
Materials: n/a. doi:10.1002/adma.201200674.
8. Tao, Hu et al. (2008-05-12). "A metamaterial absorber for the terahertz
regime: Design, fabrication and characterization" (Free PDF download).
Optics Express 16 (10): pp. 7181–7188. arXiv:0803.1646.
Bibcode:2008OExpr..16.7181T. doi:10.1364/OE.16.007181. PMID 18545422.
Retrieved 2010-01-22.
9. Yang, Z. et al. (2010). "Acoustic metamaterial panels for sound attenuation in
the 50–1000 Hz regime". Appl. Phys. Lett. 96 (4): 041906 [3 pages].
Bibcode:2010ApPhL..96d1906Y. doi:10.1063/1.3299007.
Further reading
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Alici, Kamil Boratay; Turhan, Adil Burak; Soukoulis, Costas M.; Ozbay,
Ekmel (2011). "Optically thin composite resonant absorber at the near-infrared
band: A polarization independent and spectrally broadband configuration"
(Free Article download). Optics Express 19 (15): 14260–7.
Bibcode:2011OExpr..1914260B. doi:10.1364/OE.19.014260.
PMID 21934790.
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Baker-Jarvis, James; Kim, Sung (2012). "The Interaction of Radio-Frequency
Fields with Dielectric Materials at Macroscopic to Mesoscopic Scales" (Free
PDF download). Journal of Research of the National Institute of Standards
and Technology 117: 1. doi:10.6028/jres.117.001.
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Costa, Filippo; Monorchio, Agostino; Manara, Giuliano (2010). "Analysis and
Design of Ultra Thin Electromagnetic Absorbers Comprising Resistively
Loaded High Impedance Surfaces" (free PDF download). IEEE Transactions
on Antennas and Propagation 58 (5): 1551. arXiv:1005.1553.
Bibcode:2010ITAP...58.1551C. doi:10.1109/TAP.2010.2044329.
o The above PDF download is a self-published version of this paper.
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Munk, Benedikt A. (2000). Frequency Selective Surfaces: Theory and Design.
New York: John Wiley & Sons. pp. 315–317. ISBN 0-471-37047-9. The
Salisbury screen, invented by American engineer Winfield Salisbury in 1952.
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Salisbury W. W. "Absorbent body for electromagnetic waves", United States
patent number 2599944 June 10, 1952. Also cited in Munk