Dynamic control of THz polarization modulation and multi-channel beam generation using a programmable metasurface

Area of Science:

• Terahertz (THz) technology
• Metamaterials science
• Optoelectronics

Background:

• Polarization modulation and multichannel beam generation are essential for THz communication and imaging.
• Existing methods often lack dynamic control and reconfigurability.

Purpose of the Study:

• To develop a polarization-reprogrammable coding metasurface for dynamic THz beam manipulation.
• To demonstrate flexible control over reflected THz beams using a novel metasurface design.

Main Methods:

• Utilized VO2/Au composite concentric rings (CCRs) as digital coding elements.
• Leveraged the phase-change property of VO2 (insulator to metal transition) to switch polarization states (0 and 1).
• Combined phase gradient with polarization coding for anisotropic control of multi-channel beams.

Main Results:

• Achieved polarization conversion from y-polarized to x-polarized incident waves (digital state 0).
• Maintained unchanged polarization for reflected waves in the metal state of VO2 (digital state 1).
• Demonstrated dynamic and flexible manipulation of electromagnetic (EM) reflected beams through programmable coding sequences.

Conclusions:

• The proposed metasurface offers programmable THz polarization control.
• Enables dynamic multi-channel beam steering and manipulation.
• Paves new avenues for THz polarization manipulation, signal detection, and information communication.