All‐Dielectric Multichannel Terahertz Metasurface Empowering Independent Wavefront Manipulation

Abstract

AbstractMetasurfaces have demonstrated unprecedented capabilities in modulating the polarization and phase of electromagnetic waves and formed an emerging field of research, driving the exploitation of versatile compact devices. In this work, one transmission‐mode, multichannel all‐silicon metasurface platform that can implement functionalities separately in two orthogonally polarized output fields under linearly polarized incidences is proposed, which can effectively promote the design flexibility. Specifically, a single metasurface can realize multiple independent target phase distributions carrying specific phase relationships, thus enabling different information processing in different linear polarization states. For proof‐of‐principle experimental exhibitions, a monolayer metasurface composed of silicon pillars is designed, fabricated, and characterized to demonstrate the ability of multi‐dimensional light field control, such as polarization‐switchable focusing beam. Moreover, the other designed metasurface can generate polarization‐switchable Bessel vortex beams under linearly polarized incidences, which also verifies the flexibility and practicality of such platform. This metasurface platform may lead to new optical components, involving multichannel singular beam generators, information encoders, and holographic encryption devices.