Wavelength-polarization-multiplexed multichannel perfect vortex array generator based on dielectric metasurface

Abstract

The multi-channel perfect vortex (PV) array based on metasurface has important applications in optical communication, particle manipulation, quantum optics, and other fields due to its ultra-thin structure and excellent wavefront control ability. However, it is very challenging to utilize a single metasurface to simultaneously achieve independent channel PV arrays at different wavelengths with low crosstalk and low structural complexity. Here, we propose and design a single rectangular structured metasurface based on TiO2, achieving a multi-channel PV beam array with dual-wavelength and dual-polarization multiplexing. Simulation and experimental results show that when two orthogonal linearly polarized beams with wavelengths of 532 nm and 633 nm are incident on the metasurface, clear PV arrays with corresponding topological charge arrangements can be obtained in different diffraction regions of the same observation plane. The metasurface proposed in this article can enhance the channel capacity of a PV beam array through wavelength-polarization-multiplexing, thus having important application potential in spatial information transmission, high-dimensional information storage, and secure information encryption.