Design and experimental demonstration of 3-bit digital coding metasurfaces for terahertz wave manipulation

Area of Science:

• Electromagnetics and Metamaterials
• Communications Engineering
• Applied Physics

Background:

• Future communication systems require high spectral and energy efficiency for massive user support.
• Digital coding metasurfaces bridge digital and electromagnetic (EM) domains, enabling novel communication architectures.
• Metasurfaces offer potential for low-cost, low-power devices crucial for next-generation systems.

Purpose of the Study:

• To design, fabricate, and experimentally characterize novel 3-bit digital coding metasurfaces.
• To demonstrate metasurface capabilities for wavefront modulation, focusing, and orbital angular momentum (OAM) generation.
• To explore applications in enhancing communication capacity, spectrum utilization, and security.

Main Methods:

• Design and fabrication of three types of 3-bit digital coding metasurfaces.
• Encoding phase sequences along x- and y-directions for specific EM wave manipulation.
• Experimental characterization and simulation of metalenses, focusing optical vortex (FOV) generators, and superposed FOV generators.

Main Results:

• Metalenses achieved efficient wavefront modulation and focusing in a compact planar design.
• FOV generators successfully produced vortex EM waves carrying orbital angular momentum (OAM).
• Superposed FOV generators demonstrated potential for improved spectrum utilization and interference suppression.

Conclusions:

• The proposed 3-bit digital coding metasurfaces exhibit superior performance, validated by simulation and measurement.
• The flexible EM wave manipulation and simplified design approach pave the way for intelligent communication systems.
• These metasurfaces are crucial for developing more flexible and efficient future communication technologies.