Optomechanics of chiral dielectric metasurfaces

TL;DR

This paper introduces Polarization Optomechanics, combining chiral metasurfaces with micromembranes to achieve fast, mechanically induced polarization modulation and control of light's polarization states in the near-infrared range.

Contribution

It demonstrates a novel integration of chiral metasurfaces with micromechanical elements to enable dynamic polarization control and modulation at high speeds.

Findings

Achieved ~300 kHz polarization modulation speed.

Demonstrated thermoelastic effects influence mechanical resonance.

Enabled control of polarization states via mechanical and optical interactions.

Abstract

Electromagnetic fields coupled with mechanical degrees of freedom have recently shown exceptional and innovative applications, ultimately leading to mesoscopic optomechanical devices operating in the quantum regime of motion. Simultaneously, micromechanical elements have provided new ways to enhance and manipulate the optical properties of passive photonic elements. Following this concept, in this article we show how combining a chiral metasurface with a GaAs suspended micromembrane can offer new scenarios for controlling the polarization state of near-infrared light beams. Starting from the uncommon properties of chiral metasurface to statically realize target polarization states and circular and linear dichroism, we report mechanically induced, ~300 kHz polarization modulation, which favorably compares, in terms of speed, with liquid-crystals commercial devices. Moreover, we demonstrate how the mechanical resonance can be non-trivially affected by the input light polarization (and chiral state) via a thermoelastic effect triggered by intracavity photons. This work inaugurates the field of Polarization Optomechanics, which could pave the way to fast polarimetric devices, polarization modulators and dynamically tunable chiral state generators and detectors, as well as giving access to new form of polarization nonlinearities and control.