title: Geometric phase coded metasurface: from polarization dependent directive electromagnetic wave scattering to diffusion-like scattering.
abstract: Ultrathin metasurface compromising various sub-wavelength meta-particles offers promising advantages in controlling electromagnetic wave by spatially manipulating the wavefront characteristics across the interface. The recently proposed digital coding metasurface could even simplify the design and optimization procedures due to the digitalization of the meta-particle geometry. However, current attempts to implement the digital metasurface still utilize several structural meta-particles to obtain certain electromagnetic responses, and requiring time-consuming optimization especially in multi-bits coding designs. In this regard, we present herein utilizing geometric phase based single structured meta-particle with various orientations to achieve either 1-bit or multi-bits digital metasurface. Particular electromagnetic wave scattering patterns dependent on the incident polarizations can be tailored by the encoded metasurfaces with regular sequences. On the contrast, polarization insensitive diffusion-like scattering can also been successfully achieved by digital metasurface encoded with randomly distributed coding sequences leading to substantial suppression of backward scattering in a broadband microwave frequency. The proposed digital metasurfaces provide simple designs and reveal new opportunities for controlling electromagnetic wave scattering with or without polarization dependence.
authors: Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
authors: Ke
authors: K
authors: Chen
authors: Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
authors: Yijun
authors: Y
authors: Feng
authors: Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
authors: Zhongjie
authors: Z
authors: Yang
authors: Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
authors: Li
authors: L
authors: Cui
authors: Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
authors: Junming
authors: J
authors: Zhao
authors: Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
authors: Bo
authors: B
authors: Zhu
authors: Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
authors: Tian
authors: T
authors: Jiang