When metasurface meets hologram: Principle and advances

Holography has numerous applications because of its capability of arbitrary wavefront modulation. Computer-generated holograms (CGHs) take it a big step forward. Conventional holography engineers the wavefront via phase accumulation, suffering from large size, low resolution, and small viewing angle. Metasurfaces, ultrathin two-dimensional metamaterials with subwavelength features, can manipulate the amplitude, phase, and polarization of the light, solving the above issues. In this review, advances of holography, CGH algorithms, and the principles of various metasurfaces are presented. Metasurface holography, realized by encoding the hologram in the metasurface, is investigated. Information multiplexing methods of metasurface holograms, including wavelength-multiplexed, polarization-multiplexed, complex amplitude modulated, nonlinear, and dynamic metasurfaces, are presented. The challenges and outlook of metasurface holograms are discussed.