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- Jiang, Wei, et al.
(författare)
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Room-temperature broadband quasistatic magnetic cloak
- 2017
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Ingår i: NPG ASIA MATERIALS. - : Nature Publishing Group. - 1884-4049 .- 1884-4057. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- In the past decade, invisible cloaks have experienced rapid research development in the metamaterial community driven by their revolutionary practical potentials. Among them, magnetic cloaks, which are able to conceal metallic or magnetic objects from electromagnetic induction detection, have attracted a great amount of attention. However, applications of these reported devices are limited by their low-temperature environment requirement because of the involvement of superconductors to acquire the perfect diamagnetic response. In this work, we remove this temperature hurdle by fully taking the diamagnetic features of usual metals and demonstrate a three-dimensional room temperature quasistatic magnetic cloak using a ferromagnetic metallic bilayer structure. Experimentally, our device exhibits a prominent cloaking effect in a wide frequency range from 5 to 250 kHz with a maximum field disturbance ratio < 0.5%. The practical potential is verified through a commercial handheld metal probe working at 25 kHz. Our results unambiguously show that an invisible cloak may be realized in the low-frequency region for scenarios where screening an external magnetic field without disturbance is specifically demanded.
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2. |
- Sun, Fei, et al.
(författare)
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Transformation Optics : From Classic Theory and Applications to its New Branches
- 2017
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Ingår i: Laser & Photonics reviews. - : Wiley-VCH Verlagsgesellschaft. - 1863-8880 .- 1863-8899. ; 11:6
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Forskningsöversikt (refereegranskat)abstract
- In the modern world, the ability to manipulate and control electromagnetic waves has greatly changed people's lives. Novel optical and electromagnetic phenomena and devices will lead to new scientific trends and techniques in the future. The exploration of new theories of optical design and new materials for optical engineering has attracted great attention in recent years. Transformation optics (TO) provides a new way to design optical devices with extraordinary predesigned functions such as invisibility cloaks and electromagnetic wormholes. As the development of artificial electromagnetic media (e.g. metamaterials and metasurfaces) progresses, many of these novel optical devices designed by TO have been experimentally demonstrated and used in specific applications. Starting from the basic theory of transformation optics, we review its applications, extensions, new branches and recent developments in this paper.
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