# Nonlocal Mechano-Optical Metasurfaces

## TL;DR

This paper introduces a new type of metasurface that can actively control light by combining mechanical and optical properties in a single material.

## Contribution

The novel integration of mechanical metamaterials and optical metasurfaces enables giant tunability in a single nanopatterned material.

## Key findings

- A flexible substrate with engineered cuts allows strain-induced tuning of optical resonance over a broad spectral range.
- A nanopatterned silicon membrane acts as both a mechanical metamaterial and an optical metasurface with large tunability.
- The design offers potential for tunable filters, reconfigurable lenses, and dynamic wavefront shaping.

## Abstract

Tunable metasurfaces enable active and on-demand control
over optical
wavefronts through the reconfigurable scattering of resonant nanostructures.
Here, we combine novel insights inspired by mechanical metamaterials
with the unique sensitivity of nonlocal optical resonances to interparticle
distances to achieve giant tunability in mechano-optical metasurfaces
where the mechanical metamaterial and optical metasurfaces are integrated
in a single nanopatterned material. In a first design, judiciously
engineered cuts in a flexible substrate enable large, strain-induced
extension of the interparticle spacing, tuning a high-quality-factor
resonance in a silicon nanoparticle array across a very broad spectral
range. In a second design, we eliminate the substrate and demonstrate
a nanopatterned silicon membrane that simultaneously functions as
a mechanical metamaterial and an optical metasurface with large tunability.
Our results highlight a promising route toward active metasurfaces,
with potential applications in tunable filters, reconfigurable lenses,
and dynamic wavefront shaping.