High-dimensional multi-degrees-of-freedom OAM multiplexed holography on metasurfaces enabled by dual-power-exponent multi-spiral helico-conical beams.

Optical orbital angular momentum (OAM) multiplexed holography utilizes the orthogonality of OAM modes, providing a promising approach for high-capacity information transmission. However, expanding the multiplexed dimensions and integrating devices remains challenging due to mode crosstalk and complex implementation methods. Here, we propose a dual-power-exponent multi-spiral helico-conical beam (DPE-MSHCB) with six parameters and introduce it into Pancharatnam-Berry (PB) phase metasurfaces to realize high-dimensional multi-degrees-of-freedom (multi-DoFs) OAM multiplexed holography. By systematically verifying the mode selectivity and independence of the constant K, power exponents m, n, sub-spiral number s, and normalization factor R, these parameters are introduced into holography as independent encoding DoFs, enabling parallel encoding and independent decoding of 24 target images in the six-dimensional parameter space. This approach significantly increases multiplexed channels and mode dimensions with structural simplicity, exhibiting metasurface advantages in high-dimensional OAM multiplexed holography and having potential applications in high-capacity optical communication and optical information systems.