Bound states in the continuum for optomechanical light control with dielectric metasurfaces.

We investigate a reconfigurable dielectric metasurface merging optomechanical interaction and quasi-bound states in the continuum promising for all-optical light control light. The surface consists of a dimerized high-contrast grating with a compliant bilayer structure. The optical forces induced by a control light field lead to structural deformations changing the optical response. We discuss requirements for the geometry and optical force distribution to enable an efficient optomechanical coupling, which can be exploited to tune reflectivity, phase and polarization of a beam impinging on the metasurface. Numerical results explore some tunable devices as mirrors, saturable output couplers, phase modulators and retarder plates.