Valentine Jason, Li Jensen, Zentgraf Thomas, Bartal Guy, Zhang Xiang
NSF Nano-scale Science and Engineering Center, 3112 Etcheverry Hall, University of California, Berkeley, California 94720, USA.
Nat Mater. 2009 Jul;8(7):568-71. doi: 10.1038/nmat2461. Epub 2009 Apr 29.
Invisibility devices have captured the human imagination for many years. Recent theories have proposed schemes for cloaking devices using transformation optics and conformal mapping. Metamaterials, 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 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.
隐形装置多年来一直激发着人类的想象力。最近的理论提出了利用变换光学和共形映射设计隐形斗篷的方案。超材料具有空间定制的特性，通过实现对电磁波传播的精确控制，提供了必要的介质。利用超材料，已经实现了首次微波隐形，但实现光学频率下的隐形（迈向实际隐形的关键一步）仍然难以捉摸。在此，我们报告光学隐形的首次实验演示。光学“地毯”斗篷利用准共形映射设计，通过模仿平面的反射来隐藏置于弯曲反射面下方的物体。该斗篷仅由各向同性介电材料组成，可在1400 - 1800纳米波长范围内实现宽带、低损耗隐形。
