Properties of liquids and liquid crystals in nano-scale space

Three-dimensional periodic structures of synthetic opals and various inverse opals with interconnected regular array of nano-scale voids in which liquids and liquid crystals can be infiltrated have been prepared for the study of liquids and liquid crystals confined in nano-scale spaces. One-dimensional periodic structure containing a defect layer in which liquids and liquid crystals can be introduced have also been prepared by the multi-layered SiO₂ and TiO₂ stacks. These three-dimensional and one-dimensional periodic structures containing liquids and liquid crystals exhibited novel properties as tunable photonic crystals. Utilizing these phenomena a simple apparatus to evaluate the refractive index of liquids precisely have been proposed, with which sorts of dielectric liquids can be distinguished. Kerr effect and non-linear optical effects of liquids contained in the defect layer of the one-dimensional systems have also been discussed. When the opals and inverse opals contain liquid crystals, the transmission dip and reflection peak wavelengths can be tuned by applied field. The response characteristics are different for opals and inverse opals, which can be interpreted by taking the interaction of liquid crystal molecules with the inner surface of the void into consideration. Utilizing one-dimensional systems containing liquid crystals in the defect layer a ultra-fast switching of a laser light and also in systems containing liquid crystals and fluorescent dyes a voltage tunable lasing in the wide spectral range have been demonstrated