Manipulation of Optical Encryption Metasurface Orbital Angular Momentum Holography via Multi‐Spatial Modal Basis Multiplexing

Abstract Metasurface orbital angular momentum (OAM) holography has great potential in high‐capacity information storage and encryption from its unbounded orthogonal helical modes and nanometer‐scale resolution. However, this multiplexing technique currently remains at the single degree of freedom (DoF) level, and its inherent diffraction causes the beam spreading as the OAM spiral mode index increases, which limits its applicability in areas such as high‐capacity information storage and high‐security encryption. Addressing this, we propose the concept of metasurface OAM holography with multi‐spatial modal basis multiplexing (MSMBM), which provides a multi‐DoF control method by using the multiple dimensions of spatial modal basis and OAM helical mode index to expand the information capacity of holographic display devices. Under the same OAM spiral mode index, the method can integrate OAM with different spatial mode bases as a high‐dimensional information carrier, and realize control of multiple independent DOF while maintaining image resolution. As a proof of concept, we experimentally demonstrate a meta‐hologram using a noninterleaved metasurface, which enables the reconstruction of a unique sequence of OAM‐dependent holographic images, and the information capacity is twice that of traditional OAM multiplexed holography. This breakthrough enhances information capacity and security, enabling ultra‐high‐capacity data storage and optical encryption applications.