Planar peristrophic multiplexing metasurfaces

As a promising counterpart of two-dimensional metamaterials, metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing devices. Nevertheless, the degrees of freedom (DoF) to orthogonally multiplex data have been almost exhausted. Compared with state-of-the-art methods that extensively employ the orthogonal basis such as wavelength, polarization or orbital angular momentum, we propose an unprecedented method of peristrophic multiplexing by combining the spatial frequency orthogonality with the subwavelength detour phase principle. The orthogonal relationship between the spatial frequency of incident light and the locally shifted building blocks of metasurfaces can be regarded as an additional DoF. We experimentally demonstrate the viability of the multiplexed holograms. Moreover, this newly-explored orthogonality is compatible with conventional DoFs. Our findings will contribute to the development of multiplexing metasurfaces and provide a novel solution to nanophotonics, such as large-capacity chip-scale devices and highly integrated communication.