In this paper, we propose a bilayer metasurface which is capable of launching helicity-inverted wave only in the forward direction. In order to obtain directional scattering characteristics of individual cells, we employed two layers of thin metasurfaces that are separated by a dielectric spacer. Multiple scattering analysis is used to derive design conditions for single metasurface reflectances for each polarization and it was shown that such target reflectances are realizable with split-ring aperture. The unit cell structure optimized for forward-only scattering of cross-polarization component is shown to have power extinction ratio as high as 32. The proposed structure can potentially form a supercell with reflective cells so that geometric phases of transmitted light and reflected light can be independently controlled. The proposed scheme is expected to pave a way to new types of metasurfaces with multiplexed optical functions.

Date Published: 31 October 2016
PDF: 7 pages
Proc. SPIE 10022, Holography, Diffractive Optics, and Applications VII, 100222E (31 October 2016); doi: 10.1117/12.2247798

Published in SPIE Proceedings Vol. 10022:
Holography, Diffractive Optics, and Applications VII
Yunlong Sheng; Chongxiu Yu; Changhe Zhou, Editor(s)