Díaz-Rubio Ana, Asadchy Viktar S, Elsakka Amr, Tretyakov Sergei A
Department of Electronics and Nanoengineering, Aalto University, P.O. Box 15500, FI-00076 Aalto, Finland.
Sci Adv. 2017 Aug 11;3(8):e1602714. doi: 10.1126/sciadv.1602714. eCollection 2017 Aug.
The use of the generalized Snell's law opens wide possibilities for the manipulation of transmitted and reflected wavefronts. However, known structures designed to shape reflection wavefronts suffer from significant parasitic reflections in undesired directions. We explore the limitations of the existing solutions for the design of passive planar reflectors and demonstrate that strongly nonlocal response is required for perfect performance. A new paradigm for the design of perfect reflectors based on energy surface channeling is introduced. We realize and experimentally verify a perfect design of an anomalously reflective surface using an array of rectangular metal patches backed by a metallic plate. This conceptually new mechanism for wavefront manipulation allows the design of thin perfect reflectors, offering a versatile design method applicable to other scenarios, such as focusing reflectors, surface wave manipulations, or metasurface holograms, extendable to other frequencies.
广义斯涅尔定律的应用为操控透射和反射波前开辟了广阔的可能性。然而，已知的用于塑造反射波前的结构在不期望的方向上存在显著的寄生反射。我们探究了用于设计无源平面反射器的现有解决方案的局限性，并证明完美性能需要强非局部响应。引入了一种基于能量表面通道化的完美反射器设计新范式。我们利用由金属板支撑的矩形金属贴片阵列实现并通过实验验证了异常反射表面的完美设计。这种概念上新的波前操控机制允许设计薄型完美反射器，提供了一种适用于其他场景（如聚焦反射器、表面波操控或超表面全息图）的通用设计方法，并且可扩展到其他频率。
