上海科技大学知识管理系统

Metasurfaces are extensively studied for the flexible manipulation of wavefront and polarization of electromagnetic waves with significant merits such as ultra-thin profiles and low insertion losses. However, conventional meta-devices are usually limited by achieving only single polarization modulation, and it is challenging to achieve mixed polarization and wavefront manipulation in a single metasurface. Here, a single-layer anisotropic metasurface for independent wavefront manipulation in multiple polarization channels is presented. The meta-atom is composed of two orthogonal dumbbell-shaped metal patches placed on the top of a dielectric layer with grounded plane on the bottom. The reflective phases of the two orthogonal linearly polarized waves can be independently manipulated by changing the dimensions of the dumbbell-shaped resonator. As a result, not only the propagation phase but also the polarization state of the outgoing wave can be manipulated independently as desired. As proof of concept, a metasurface is designed for converging the reflection beams of four polarization states to specific positions for four-focus holographic imaging. The measured results are in good agreements with simulated ones, verifying the independent wavefront manipulations with arbitrary polarization conversions.