Mechanically reconfigurable multi-functional meta-optics studied at microwave frequencies

Area of Science:

• Optics and Photonics
• Metamaterials Science
• Mechanical Engineering

Background:

• Metasurfaces enable thinner optical components and multi-functional devices.
• Traditional metasurfaces often compromise performance in multi-functional and broadband applications.
• Three-dimensional (3D) metastructures offer enhanced design flexibility while maintaining minimal thickness.

Purpose of the Study:

• To explore mechanically reconfigurable 3D metastructures.
• To achieve multiple optical functionalities including focusing, spectral demultiplexing, and polarization sorting.
• To demonstrate these functionalities through mechanical configuration.

Main Methods:

• Adjoint-based topology optimization for device design.
• Fabrication using 3D printing.
• Experimental validation at microwave frequencies (7.6-11.6 GHz) in an anechoic chamber.

Main Results:

• Designed and fabricated three proof-of-concept devices: a rotatable device, a device with rotating squares, and a shearing-based device.
• Demonstrated mechanical reconfigurability for achieving diverse optical functions.
• Validated device performance through microwave measurements.

Conclusions:

• Mechanically reconfigurable 3D metastructures are a promising platform for advanced optical applications.
• This approach overcomes limitations of traditional metasurfaces in multi-functional and broadband scenarios.
• The developed devices showcase the potential for tunable and reconfigurable optical functionalities.