超表面相位调控原理及应用

Principles and applications of metasurfaces with phase modulation

超构表面是一种基于亚波长结构的功能膜层器件,也称超表面或二维超构材料。超构表面可在平面化的亚波长结构内产生异常的相位突变,从而为包括大口径平面成像、电磁虚拟赋形、大视场全息显示等应用提供有效手段。与传统的光学器件相比,超构表面器件具有亚波长尺度相位、振幅、偏振任意调控,轻薄、易集成、低损耗、表面可共形设计等诸多优点,因而受到广泛关注。本文对超构表面的相位调控原理进行分析,并据此对现有的超构表面进行分类,同时介绍了各类超构表面器件的特点和应用,最后对超构表面领域面临的挑战及有待进一步拓展的方向进行展望。

Metasurfaces, the equivalent two-dimensional （2D） metamaterials, are thin-film functional devices con- structed by subwavelength structures. Abrupt phase changes can be obtained in the planar metasurface structures over the subwavelength scale, which provide a new avenue to enable a variety of applications, including large scale planar imaging, electromagnetic virtual shaping and holographic display with large field of view. The arbitrary mod- ulation abilities of phase, amplitude and polarization at the subwavelength scale, also the light weight, low loss, integratable and conformable design make the metasurfaces very attractive, compared to the traditional optical de- vices. In this paper, we review the mechanisms of the phase modulation and classify the metasurfaces based on them. The properties and the applications of each type of metasurfaces are also detailedly discussed. The chal- lenges faced by metasurfaces and the areas which need to be further extended are also summarized.