Reprogrammable Graphene-based Metasurface Mirror with Adaptive Focal Point for THz Imaging

Area of Science:

• Optics and Photonics
• Materials Science
• Electromagnetics

Background:

• Metasurfaces enable ultra-thin optical components but typically have fixed focal points.
• Conventional metasurfaces lack reconfigurability, limiting their practical applications in dynamic focusing scenarios.

Purpose of the Study:

• To develop a flat, reprogrammable reflective component for dynamic focusing of terahertz waves in the near-field.
• To overcome the limitations of non-adaptive conventional metasurfaces by introducing reconfigurable functionality.

Main Methods:

• Proposed a graphene-based unit cell exhibiting tunable phase characteristics.
• Employed the coding metasurface approach to design the required phase profile for targeted near-field focusing.
• Utilized terahertz (THz) wave manipulation techniques.

Main Results:

• The designed component operates near the diffraction limit, achieving high focusing accuracy and range.
• Demonstrated the component's ability to dynamically reprogram its focal point in the terahertz near-field.
• Achieved low focusing error and high focusing efficiency.

Conclusions:

• The reprogrammable graphene metasurface offers a viable solution for dynamic terahertz focusing.
• This technology can enable compact terahertz scanning and imaging systems.
• Potential applications include novel reconfigurable components for terahertz wireless communications.