Tunable Polarization Conversion and Rotation based on a Reconfigurable Metasurface.

Area of Science:

• Optics and Photonics
• Metamaterials
• Terahertz (THz) Technology

Background:

• Polarization is a fundamental property of electromagnetic (EM) waves, crucial for numerous optical applications.
• Tailoring EM wave polarization is essential for advanced functionalities in fields like imaging and sensing.
• Existing metasurfaces often offer fixed polarization manipulation, limiting their adaptability.

Purpose of the Study:

• To develop and demonstrate a reconfigurable metasurface for dynamic polarization control in the THz regime.
• To achieve simultaneous polarization conversion and polarization rotation using a single device.
• To explore the potential of micro-electro-mechanical-systems (MEMS) for active metasurface reconfiguration.

Main Methods:

• Fabrication of a novel metasurface designed for THz wave interaction.
• Integration of micro-electro-mechanical-systems (MEMS) for active reconfiguration of the metasurface.
• Experimental characterization of polarization conversion and rotation across different THz frequencies.

Main Results:

• Demonstrated tunable cross-polarization transmittance from 0% to 28% at 2.66 THz.
• Achieved effective tuning of the polarization rotation angle from -12.8° to 13.1° at 1.78 THz.
• Verified the bi-functional capability of the metasurface for both conversion and rotation.

Conclusions:

• The developed reconfigurable metasurface offers dynamic control over THz wave polarization.
• MEMS actuation provides a viable mechanism for active tuning of metasurface functionalities.
• This tunable bi-functional device holds promise for diverse applications including THz imaging, microscopy, and material analysis.