Reconfigurable three-channel terahertz reflective metasurface

Area of Science:

• Metasurfaces
• Terahertz (THz) Technology
• Electromagnetics

Background:

• Metasurfaces offer advanced control over electromagnetic waves.
• Reconfigurable metasurfaces are crucial for dynamic wave manipulation.
• Terahertz technology demands efficient and versatile devices.

Purpose of the Study:

• To propose a reconfigurable three-channel terahertz reflective metasurface.
• To demonstrate complex wavefront control using the metasurface.
• To provide a design for efficient, multi-functional terahertz devices.

Main Methods:

• Design of a six-layer sandwich structure metasurface unit with composite resonators and double E-shaped structures.
• Utilizing geometric phase principles for 3-bit phase quantization.
• Employing temperature and illumination control to alter phase change materials (vanadium dioxide, photosensitive silicon).

Main Results:

• The metasurface achieves three-channel reflection of circularly polarized terahertz waves.
• Demonstrated simultaneous complex wavefront control, including vortex beams, offset focusing, and holographic imaging.
• Phase distribution calculated using convolution theorem, complex addition theorem, focusing theorem, and Gerchberg-Saxton algorithm.

Conclusions:

• The proposed metasurface is structurally simple and functionally reconfigurable.
• It enables efficient, lightweight, low-cost, and multi-functional terahertz devices.
• Offers a valuable reference for future terahertz device design.