Tunable transmissive terahertz polarization rotator based on a resonance-decoupled metal-VO₂ hybrid metasurface

Area of Science:

• Metasurfaces
• Terahertz (THz) optics
• Materials science

Background:

• Novel tunable materials like vanadium dioxide (VO2) enhance terahertz (THz) metasurfaces for dynamic applications.
• Existing transmissive THz linear polarization rotators often have complex structures and limited performance (low transmittance, poor modulation depth).

Purpose of the Study:

• To present a tunable transmissive THz linear polarization rotator based on VO2.
• To demonstrate temperature-controlled dynamic tunability of the rotation angle and polarization states.

Main Methods:

• Theoretical analysis and numerical simulations were employed.
• The study utilized the temperature-dependent conductivity of VO2 to control terahertz wave polarization.
• Decoupled magnetic and electric dipole resonances in a hybrid metasurface were analyzed.

Main Results:

• Achieved a tunable rotation angle range from 40° to -36° with transmittance above 66.9%.
• Demonstrated independent tuning of rotation angles in insulating and metallic states (0°∼90° difference).
• Proposed a polarization-selective dynamic display using temperature variation.

Conclusions:

• The VO2-based rotator offers excellent performance for tunable THz polarization modulation.
• The design principles, including decoupled resonances and constructive interference, inspire future THz device development.
• The proposed device enables switchable polarization patterns for advanced THz applications.