Sliding-tunable terahertz beam meta-deflector based on a 3D-printed bilayer.

Area of Science:

• Metamaterials and Nanophotonics
• Terahertz (THz) Technology
• Optical Engineering

Background:

• Terahertz (THz) devices require rapid preparation and tunable functionalities.
• Existing THz beam deflectors often lack multifunctionality and tunability.
• Metasurfaces offer a promising platform for advanced optical device design.

Purpose of the Study:

• To propose and demonstrate a tunable terahertz beam meta-deflector (BMD) based on a bilayer metasurface.
• To achieve continuous beam deflection with additional functions like splitting and focusing.
• To enable rapid switching between different functionalities by replacing functional phases.

Main Methods:

• Design of a bilayer metasurface doublet for THz beam deflection.
• Superimposition of functional phases on one layer and sliding of the other layer.
• Fabrication of prototype devices using 3D printing.
• Experimental characterization of beam deflection, splitting, and focusing performance.

Main Results:

• Demonstrated a splitting BMD (s-BMD) achieving ±26.96° deflection and 38.94°-44.11° splitting angles.
• Demonstrated a focusing BMD (f-BMD) achieving ±30.76° focus deflection.
• Validated the capability for continuous beam deflection and tunable functionalities.
• Confirmed rapid switching between functions by replacing the functional phase.

Conclusions:

• The proposed bilayer metasurface BMD provides a multifunctional and tunable solution for THz beam manipulation.
• The 3D printing fabrication method allows for rapid prototyping.
• The device shows significant potential for applications in THz communication and imaging systems.