Polarization-Dependent Multichannel Holography on Pixel-Optimized Phase-Grafted Metasurface

Polarization multiplexing has been recognized as a promising technique to improve the information capacity of metasurface holography. However, current methods suffer from high structural complexity and challenges in independent modulation of multiple channels. Here, we propose a phase grafting approach for the design of a single-layer metasurfaces that enables polarization-dependent multichannel far-field holography. In this approach, we vertically splice half of a dynamic phase and half of a Pancharatnam–Berry-dynamic-combined phase into a complete profile, so that both the linear polarization and the circular polarization can be utilized to independently carry image information. Moreover, in order to improve the quality of the reconstructed holographic images, we devise a hybrid phase retrieval algorithm where a pixel-level discrete search and optimization is appended to the traditional Gerchberg–Saxton algorithm. Simulation results demonstrate the effectiveness of our polarization-dependent far-field holography scheme, which may find applications in encryption, imaging, and entertainment.