Multi‐Channel Holography via Phase‐Switchable Cascaded Liquid Crystals for Optical Secret Sharing

Abstract

Metasurface holography, with its compact structural design and multi‐dimensional multiplexing capabilities, has demonstrated great potential in dynamic display and data storage applications. However, the approach of achieving multiplexing by adjusting different properties of the incident light has nearly exhausted the multiplexing dimensions of metasurfaces, severely hindering the development of information‐dense planar diffractive optical devices. Here, the concept of cascaded multiplexing channels is introduced, achieving switchable holographic displays through continuous pixel‐level lateral displacement between the layers of two closely stacked diffractive optical devices. To achieve this, a progressive optimization algorithm is developed to enhance the efficiency of optimizing phase profiles for each layer. As a proof of concept, a cascaded liquid crystal (LC) platform based on Pancharatnam‐Berry (PB) phase modulation is experimentally demonstrated, supporting up to 12 independent, nearly crosstalk‐free holographic display channels. Furthermore, by integrating traditional multiplexing techniques, an optical secret sharing platform is designed and demonstrated, which can achieve secure transmission and storage of high‐capacity information. This work introduces a new multiplexing dimension for compact holographic optical devices, with promising applications in the fields of optical storage, display, encryption, and anti‐counterfeiting.