Dielectric Metasurfaces for Complete Control of Phase, Amplitude, and Polarization

Abstract The achievable functionalities of metasurfaces are mainly determined by the capability of their unit cells to control the local electromagnetic responses. To realize full control over light, it is highly desired to find a kind of unit cell that can achieve complete control of the phase, amplitude, and polarization, which remains a big challenge and cannot be fully replaced with iteration algorithms. Here, such control is achieved by exploiting interference in a dielectric unit cell composed of multiple meta‐atoms, namely, a meta‐molecule. This strategy provides sufficient effective geometric degrees of freedom within the meta‐molecule to enable full control over its optical properties, as is demonstrated here with a complete meta‐molecule database. As a proof‐of‐concept demonstration, polarization‐independent, polarization‐dependent, and vectorial meta‐holograms are proposed and experimentally characterized. High imaging quality is achieved in both the measured intensity and phase distributions. This is allowed by the ability of the meta‐molecules to fully record the information of the target images. This strategy opens a direct way toward optical devices with various desirable functionalities.