Zheng Bin, Zhu Rongrong, Jing Liqiao, Yang Yihao, Shen Lian, Wang Huaping, Wang Zuojia, Zhang Xianmin, Liu Xu, Li Erping, Chen Hongsheng
State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 China.
The Electromagnetics Academy at Zhejiang University College of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China.
Adv Sci (Weinh). 2018 Apr 14;5(6):1800056. doi: 10.1002/advs.201800056. eCollection 2018 Jun.
The concept of an invisibility cloak is a fixture of science fiction, fantasy, and the collective imagination. However, a real device that can hide an object from sight in visible light from absolutely any viewpoint would be extremely challenging to build. The main obstacle to creating such a cloak is the coupling of the electromagnetic components of light, which would necessitate the use of complex materials with specific permittivity and permeability tensors. Previous cloaking solutions have involved circumventing this obstacle by functioning either in static (or quasistatic) fields where these electromagnetic components are uncoupled or in diffusive light scattering media where complex materials are not required. In this paper, concealing a large-scale spherical object from human sight from three orthogonal directions is reported. This result is achieved by developing a 3D homogeneous polyhedral transformation and a spatially invariant refractive index discretization that considerably reduce the coupling of the electromagnetic components of visible light. This approach allows for a major simplification in the design of 3D invisibility cloaks, which can now be created at a large scale using homogeneous and isotropic materials.
隐形斗篷的概念是科幻小说、奇幻作品以及集体想象中的常客。然而，要制造出一种能让物体在可见光下从任何视角都完全隐形的真实装置极具挑战性。制造这种斗篷的主要障碍在于光的电磁成分的耦合，这就需要使用具有特定介电常数和磁导率张量的复杂材料。以往的隐形解决方案要么是在这些电磁成分未耦合的静态（或准静态）场中发挥作用，要么是在不需要复杂材料的漫射光散射介质中发挥作用，以此来规避这一障碍。在本文中，报告了从三个正交方向将一个大型球形物体隐藏于人类视线之外的成果。这一成果是通过开发一种三维均匀多面体变换和一种空间不变折射率离散化实现的，它们能大幅降低可见光电磁成分的耦合。这种方法使得三维隐形斗篷的设计得以大幅简化，现在可以使用均匀且各向同性的材料大规模制造。
