Uniform liquid crystal alignment on metallic nanohole arrays by vapor-phase deposition of silane coupling agent

Uniform homeotropic alignment of nematic liquid crystals is achieved on a square array of metallic nanoholes through vapor-phase deposition of a fluorinated silane-coupling agent. We show through polarization optical microscopy and optical spectroscopy that the monolayer formed can induce homeotropic alignment on the nanohole array without disturbing its optical properties. The proposed technique is a step towards realizing electro-tunable metamaterials with controlled liquid crystal orientation.