Observation of 2D omnidirectional invisibility from an electrically large cluster under TE polarization.
Observation of 2D omnidirectional invisibility from an electrically large cluster under TE polarization.
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DOI：
10.1364/oe.409731
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发表时间：
2020-11
期刊：
影响因子：
3.8
通讯作者：
Xiaojun Hu;Ran Li;L. Peng;Rui Wang;J. Huangfu;L. Ran;Dexin Ye
中科院分区：
文献类型：
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作者：
Xiaojun Hu;Ran Li;L. Peng;Rui Wang;J. Huangfu;L. Ran;Dexin Ye
在自由空间中完全不可见的概念意味着物体既不反射也不折射来自任意方向的光波，无论其形状和大小如何。实现这种特殊现象的最佳解决方案是将物体的本构参数调整为与空气相同。特别是，通过覆盖一些额外的结构来从现有对象呈现零消光对于实际实现是重要的，这是具有挑战性的。在这里，我们证明并提出，一个薄的金属线可以被调谐到TE极化下的空气一样，与外部外壳的帮助。这是通过具有独立可控的电和磁响应的精确色散工程来实现的。因此，由多根细线组成的电大尺寸团簇可以安全地隐藏在自由空间中，而不需要任何宏观隐身结构，这一点通过全波模拟和实验得到了验证。在一个电大尺寸飞机模型上的测试结果表明，在所设计的频率范围内，该隐身器具有良好的二维全向隐身性能。这种提出的超材料将有助于通过额外的电线（或管道）增强设备（或系统）的机械稳定性，导电性和散热性，而不会干扰其电磁特性。
The concept of perfect invisibility in free space implies an object neither reflects nor refracts optical waves coming from arbitrary directions, regardless of its shape and size. An optimal solution to realize such a peculiar phenomenon is to tune the constitutive parameters of the object to be identical to air. In particular, to render zero extinction from an existing object by covering some additional structures, is of importance for practical implementations, which is challenging. Here, we demonstrate and propose that a thin metallic wire can be tuned to be air-like under TE polarization, with the aid of an external enclosure. This is achieved through a precise dispersion engineering with independently controllable electric and magnetic responses. Consequently, an electrically large cluster composed of multiple thin wires can be safely hidden in free space, without any macroscopic cloaking structure, which is verified by full-wave simulations and experiments. The measured results on an electrically large airplane-like sample show the excellent performance of 2D omnidirectional invisibility at the designed frequency. This proposed metamaterial would be helpful in enhancing the mechanical stability, electrical conduction, and heat dissipation of a device (or system) by extra wires (or pipes), without disturbing its electromagnetic characteristics.