Metasurfaces embedded in inhomogeneously aligned liquid crystals

Integrating metasurfaces into Liquid Crystal (LCs) cells is a suitable pathway for the realization of tunable optical devices. In such cells, the initial alignment of the LC molecules can be controlled by photoalignment layers. Here, we study the integration of a homogeneous silicon nanocylinder metasurface into an inhomogeneously aligned LC. To locally induce a change in the alignment direction of the LC starting from homogeneous exposure with x-polarized blue light, the photoalignment layers are re-exposed with structured y-polarized blue light. In the spatially-resolved transmittance spectra of the LC integrated metasurface, the double-exposed region can be identified by wavelength-dependent transmittance changes induced by the reorientation of the LC molecules and corresponding spectral shifts of the metasurface Mie resonances. Our results demonstrate that metasurfaces embedded into inhomogeneously aligned LCs allow for the controlled implementation of arbitrary spatial patterns. Possible applications include reconfigurable images, holograms, gratings and Fresnel zone plates.