Abstract
Establishing and approaching the fundamental limit of orbital-angular-momentum (OAM) multiplexing are necessary and increasingly urgent for current multiple-input multiple-output research. In this work, we elaborate the fundamental limit in terms of independent scattering channels (or the degrees of freedom of scattered fields) through angular-spectral analysis, in conjunction with a rigorous Green's function method. The scattering-channel limit is universal for arbitrary spatial-mode multiplexing, which is launched by a planar electromagnetic device, such as antenna, metasurface, etc., with a predefined physical size. As a proof of concept, we demonstrate both theoretically and experimentally the limit by a phase-only metasurface hologram that transforms orthogonal OAM modes to plane-wave modes scattered at critically separated angular-spectral regions. Particularly, a minimax optimization algorithm is applied to suppress angular-spectrum aliasing, achieving good performances in both full-wave simulation and experimental measurement at microwave frequencies. This work offers a theoretical upper bound and corresponding approach route for engineering designs of OAM multiplexing.
Recommended Citation
S. S. Yuan and J. Wu and M. L. Chen and Z. Lan and L. Zhang and S. Sun and Z. Huang and X. Chen and S. Zheng and L. J. Jiang and X. Zhang and W. E. Sha, "Approaching The Fundamental Limit Of Orbital-Angular-Momentum Multiplexing Through A Hologram Metasurface," Physical Review Applied, vol. 16, no. 6, article no. 064042, American Physical Society, Dec 2021.
The definitive version is available at https://doi.org/10.1103/PhysRevApplied.16.064042
Department(s)
Electrical and Computer Engineering
International Standard Serial Number (ISSN)
2331-7019
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 American Physical Society, All rights reserved.
Publication Date
01 Dec 2021
