Topology optimized multi-functional mechanically reconfigurable meta-optics studied at microwave frequencies

TL;DR

This paper presents the design and experimental validation of 3D mechanically reconfigurable metastructures at microwave frequencies that perform multiple optical functions such as focusing, spectral demultiplexing, and polarization sorting.

Contribution

It introduces a novel approach using topology optimization for designing 3D reconfigurable metastructures that maintain high performance across multiple functionalities.

Findings

Successful fabrication and testing of reconfigurable metastructures at microwave frequencies.

Demonstration of multifunctionality including focusing, spectral demultiplexing, and polarization sorting.

Validation of design concepts through measurements in an anechoic chamber.

Abstract

Metasurfaces advanced the field of optics by reducing the thickness of optical components and merging multiple functionalities into a single layer device. However, this generally comes with a reduction in performance, especially for multifunctional and broadband applications. Three-dimensional metastructures can provide the necessary degrees of freedom for advanced applications, while maintaining minimal thickness. This work explores 3D mechanically reconfigurable devices that perform focusing, spectral demultiplexing, and polarization sorting based on mechanical configuration. As proof of concept, a rotatable device, auxetic device, and a shearing-based device are designed with adjoint-based topology optimization, 3D-printed, and measured at microwave frequencies (7.6-11.6 GHz) in an anechoic chamber.