# High-dimensional multiplexing through vortex electromagnetic wave manipulation by space-time-coding metasurfaces

## TL;DR

This paper introduces a new metasurface technology that enables high-dimensional wireless communication by combining multiple properties of electromagnetic waves.

## Contribution

The paper presents a dual-polarized space-time-coding metasurface that simplifies high-dimensional communication systems.

## Key findings

- DASM produces coaxial OAM beams through a single aperture across multiple domains.
- The framework integrates OAM, polarization, and frequency multiplexing for increased channel capacity.
- Direct modulation of OAM beams eliminates the need for external modulators.

## Abstract

Orbital angular momentum (OAM) is a fundamental property of light, with widespread applications across various fields, from quantum mechanics to advanced imaging and telecommunications. The inherent orthogonality of OAM beams allows information multiplexing in unique, high-dimensional states. However, conventional OAM-based systems encounter long-standing integration and scalability challenges due to the heavy reliance on complex optical components and redundant radio frequency chains for multi-channel transmission. Here, we propose a dual-polarized asynchronous space-time-coding metasurface (DASM) for producing coaxial OAM beams in multiple physical domains through a single aperture. By synergistically combining OAM, polarization, and frequency division multiplexing, DASM constructs a high-dimensional communication framework, dramatically increasing the number of supported channels. Notably, DASM further streamlines the framework by directly modulating the information carried by OAM beams, eliminating the need for complicated external modulators. The high-dimensional multiplexing framework offers a simplified, versatile, and efficient solution for substantial development in wireless communications capacity and scalability.

A programmable metasurface enables direct information modulation and high-dimensional communications by multiplexing OAM, polarization, and frequency.