Omnidirectional Angular‐Multiplexed Meta‐Holography via Arbitrary Spatial Rays

Abstract Metasurfaces exhibit exceptional light manipulation capabilities, with extensive exploration and utilization of various optical parameters, including wavelength, intensity, polarization, orbital angular momentum, etc, enabling novel degrees of freedom (DoF) for optical multiplexing. Serving as an essential optical parameter, the DoF for arbitrary incident angles, however, has not been fully exploited and remains a critical challenge due to the absence of effective phase encoding and fusing mechanisms. Here, the DoF of arbitrary spatial incident angles (including azimuth angle and elevation angle) is originally proposed, achieving full utilization of arbitrary angular DoF via the implementation of effective phase encoding in the entire angular space. Specifically, by correlating the meta‐atom displacements with arbitrarily predefined angles for spatial rays and optimizing their detour phases through the gradient descent algorithm, up to 22 channels of augmented reality (AR) holographic images within the observation sight are successfully demonstrated. Both numerical simulations and experimental results demonstrate that effective phase encoding can be successfully implemented for the newly introduced DoF with arbitrary incident angles. The demonstrated arbitrary full‐angle multiplexed holography exhibits high information density and quality, which shows promising potential for practical applications in data storage, virtual/augmented reality, and optical encryption.