Off-axis metasurface hologram based on the principle of interference

Metasurface holograms based on flat optical devices have garnered increasing interest for their ability to miniaturize optical devices and systems. However, current off-axis metasurface holograms based on the Gerchberg-Saxton algorithm, superimpose additional phase in their design process, leading to holographic image of varying period in the reconstruction plane and an inability to create virtual images. We present an off-axis metasurface hologram created using the sparse Fourier transform method, which is based on interferometric holography theory. High-transmittance materials, such as SiO2 2 and Si3N4, 3 N 4 , are employed for the substrate and phase control units, respectively, operating at a wavelength of 635 nm. Numerical findings indicate that the unit cells designed achieve an average transmittance of 99.72%. Additionally, the overall transmittance of the constructed metasurface holograms reaches 80%. Furthermore, the design of the off-axis metasurface hologram effectively reproduces distinct holographic images. This study could provide an approach for designing off-axis metasurface holograms and broaden their range of applications.