Directional vortex beam generation through all-dielectric transmission metasurface

Area of Science:

• Electromagnetics and Optics
• Metamaterials Science

Background:

• Orbital angular momentum (OAM) offers a unique dimension for information transmission in electromagnetic waves.
• Vortex beams, while powerful, suffer from divergence, limiting their practical application distance.
• Effective methods for generating directional vortex beams are scarce, hindering advancements in wireless communication and radar.

Purpose of the Study:

• To propose and verify a novel method for generating directional vortex beams using metasurfaces.
• To address the beam divergence issue inherent in vortex waves.
• To enable enhanced long-distance transmission and far-field applications of vortex waves.

Main Methods:

• Superposition of multiple vortex beams with distinct OAM modes.
• Design and implementation of a shared-aperture all-dielectric metasurface.
• Simulation, fabrication, and measurement of the metasurface prototype in the millimeter wave band.

Main Results:

• Successful generation of a directional vortex beam using the designed metasurface.
• Demonstration of control over orbital angular momentum (OAM) modes.
• Experimental validation of the metasurface's performance in the millimeter wave spectrum.

Conclusions:

• The proposed metasurface approach effectively generates directional vortex beams.
• This method enhances transmission distance and expands far-field applications for vortex waves.
• The technology holds significant potential for advancements in radar and wireless communication systems.