Four-channel holographic metasurface based on frequency-angle multiplexing

Abstract

Due to the powerful ability of metasurfaces to manipulate light fields, various optical parameters have been widely explored and studied through precise design of metasurface units. However, the angle of incidence, which is one of the important optical parameters, has not been fully investigated for multiplexing due to the lack of coding degrees of freedom. Here, the scheme of four-channel holographic metasurface based on frequency-angle multiplexing is proposed to achieve independent display of multiple images at different frequencies and angles. The metasurface units used are Metal-Insulator-Metal structures that can effectively manipulate the electromagnetic wave's amplitude in the reflection space to accommodate various operating frequencies and angles of incidence. The effectiveness of the proposed four-channel holographic scheme is verified by encoding four independent amplitude image information into a metasurface array. The four-channel scheme proposed in this paper successfully breaks the limitation of angular correlation and improves the density and capacity of information storage. This not only provides a higher degree of freedom and flexibility for multi-channel metasurface holographic imaging, but also holds significant importance for advancing optical information processing and display technologies. It is believed that the metasurface based on frequency-angle multiplexing can easily find more promising applications, including electromagnetic wavefront control, encryption/ concealment of optical information, and multifunctional switchable devices.