An optical cloak made of dielectrics
An optical cloak made of dielectrics
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DOI：
10.1038/nmat2461
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发表时间：
2009-07-01
期刊：
影响因子：
41.2
通讯作者：
Zhang, Xiang
中科院分区：
文献类型：
--
作者：
Valentine, Jason;Li, Jensen;Zhang, Xiang
多年来，隐形设备一直吸引着人类的想象力。最近的理论已经提出了利用变换光学和保角变换来隐身器件的方案(1-4)。具有空间定制特性的超材料(5，6)能够精确控制电磁波的流动，从而提供了必要的介质。使用超材料，已经实现了第一个微波隐身(7)，但实现光学频率隐身，这是实现实际隐身的关键一步，仍然难以捉摸。在这里，我们报道了光学隐身的第一个实验演示。光学“地毯”斗篷的设计使用准保角变换，通过模仿平坦表面的反射来隐藏放置在曲面反射表面下的物体。该斗篷仅由各向同性介质材料组成，可以在1400-1800 nm的波长范围内实现宽带和低损耗的不可见性。
Invisibility devices have captured the human imagination for many years. Recent theories have proposed schemes for cloaking devices using transformation optics and conformal mapping(1-4). Metamaterials(5,6), with spatially tailored properties, have provided the necessary medium by enabling precise control over the flow of electromagnetic waves. Using metamaterials, the first microwave cloaking has been achieved(7) but the realization of cloaking at optical frequencies, a key step towards achieving actual invisibility, has remained elusive. Here, we report the first experimental demonstration of optical cloaking. The optical 'carpet' cloak is designed using quasi-conformal mapping to conceal an object that is placed under a curved reflecting surface by imitating the reflection of a flat surface. The cloak consists only of isotropic dielectric materials, which enables broadband and low-loss invisibility at a wavelength range of 1,400-1,800 nm.