Spatially Controlled All-Optical Switching of Liquid-Crystal-Empowered Metasurfaces.

Embedding metasurfaces in liquid crystal (LC) cells is a promising technique for realizing tunable optical functionalities. Here, we demonstrate spatially controlled all-optical switching of the optical response of a homogeneous silicon nanocylinder metasurface featuring various Mie-type resonances in the spectral range between 670 and 720 nm integrated in a nematic LC cell. The initial alignment of the LC molecules is controlled by photoalignment layers, where the alignment direction is defined by homogeneous exposure with linearly polarized light at a 450 nm wavelength.