3-D Manipulation of Dual-Helical Electromagnetic Wavefronts With a Noninterleaved Metasurface
Zhenfei Li, Dajun Zhang, Ji Liu, Jin Zhang, Linda Shao, Xiong Wang, Ronghong Jin, Weiren Zhu
Abstract
While electromagnetic (EM) metasurfaces have been extensively studied for wavefront manipulations, the real 3-D manipulation of wavefront remains challenging. In this article, an advanced strategy of noninterleaved multitasked metaplexer for 3-D manipulation of dual-helical EM wavefronts is reported. We first develop a general method to derive the metasurface phase distribution required to form the desired 3-D electric field patterns. Then, the spin-decoupled meta-atoms are designed to achieve this goal and further increase the degrees of freedom in EM manipulation. As a proof of concept, cascaded multiplane digital images in the propagation direction are employed as the 3-D wavefronts, which are encoded into the spin-decoupled meta-atoms array, making the outputting circularly polarized waves carrying different image information at different planes. Both the simulations and experiments verify the desirable 3-D wavefront manipulation capacities of our strategy for dual-helical states. Besides, this scheme can be further extended to achieve arbitrary energy allocation in 3-D space for dual-helical EM waves. Our strategy paves an alternative route for applications such as multiple-input multiple-output (MIMO) communications, multitarget radar detection, information storage, as well as 3-D microwave imaging.