超构表面高效调控电磁波

实现自由调控电磁波不仅具有重要的科学研究意义,而且是通讯、能源、国防等领域的迫切需求。为了解决自然材料调控电磁波能力受限的问题,人们提出了人工超构材料这一新概念,实现了负折射、光学隐身等奇异的电磁效应。然而,经过多年的发展,超构材料仍存在结构复杂、损耗偏高、难以集成调谐等挑战。最近,本团队与国际同行一起提出了超构表面的新概念。超构表面基于电磁波在平面微结构上散射时获得的界面相位突变,充分利用人工微结构的"排列序构"这一自由度,实现了对电磁波振幅、相位、偏振及波前分布的有效调控,克服了超构材料遇到的瓶颈问题。本文主要回顾了本团队在偏振调控、波前调控及动态调控等方面开展的创新性研究。

High-Efficiency Manipulations on Electromagnetic Waves with Metasurfaces

Freely controlling electromagnetic(EM) waves in desired manners are not only highly important for scientific researches, but also an urgent need in the fields of communications, energy, national defense, etc. To overcome the limitations of natural materials on controlling EM waves, people proposed to construct artificial metamaterials based on subwavelength-sized microstructures with tailored EM properties. Metamaterials have exhibited many fascinating EM effects, such as negative refraction, optical cloaking, and so on. However, after years of development, metamaterials still suffer from many challenges including complexities in structures, high losses, difficulties in optical integrations, etc. Recently, together with other scientists, we proposed the concept of metasurfaces. Utilizing the abrupt phase changes of EM wave scatterings at the meta-atoms and fully exploring the microscopic order of the meta-atoms arrangement, metasurfaces have exhibited much stronger control capabilities on EM wave amplitude, phase, polarization and wavefront distribute, overcoming the bottleneck issues faced by bulk metamaterials. In this article, we will mainly review our key research works on using metasurfaces to control EM waves, including polarization control, wavefront control and dynamic control.