The authors have demonstrated the local alignment of nematic liquid crystal with local micro-grating structure fabricated by the curing of an ultraviolet curable material via a three dimensional micro-fabrication technique known as two photon excitation direct laser writing [1]. The molecular alignment of the nematic liquid crystals on the fabricated micro-grating structures was firstly investigated by the observations of a local twisted nematic region in a liquid crystal cell made of a substrate with locally fabricated micro-grating structure and a counter substrate with rubbed polyimide. The optical polarizing microscope observation of the micro-grating structures indicated that liquid crystals molecules have aligned parallel to the grooves of the micro-grating structure and that local alignment was successfully achieved. The alignment characteristics of the liquid crystals on these micro-gratings was also investigated and discussed quantitatively in details through the measurement of anchoring energy by the conventional torque balance method and the Berreman method. The azimuthal anchoring energy for the micro-grating was found to be in the order of 10-6 J/m2 and inversely proportional to the grating period.

Multicolor light emitting diodes (LEDs) which emit red (R), green (G) and blue (B) light have been realized by stacking a two-color emission part on a single-color emission part. The former part consists of two emissive layers of red and blue light, which can be selected by changing the polarity of applied field. The latter part consists of a single-color emission part which emits green light. The emission from the diode in the whole visible spectral range can be modulated by the combination of applying various voltages to the two-color and to the single-color emission parts, separately.

Electrical and optical properties of organic multilayer structure have been investigated. Two types of current-voltage characteristics have been found for thin multilayer structure of organic films. Optical property and its application for electroluminescent diode have been presented. The diode characteristics have been discussed in terms of energy band scheme.

The authors describe a method to produce gold nanoparticle-dispersed liquid crystals by means of sputtering, and discuss how the presence of gold nanoparticles affect the electro-optic response of the host liquid crystal. The method exploits the fact that liquid crystals possess low vapor pressures which allow them to undergo the sputtering process, and the target material is sputtered directly on the liquid crystal in a reduced air pressure environment. The sample attained a red-brownish color after sputtering, but no aggregations were observed in the samples kept in the liquid crystal phase. Polarization optical microscopy of the sample placed in a conventional sandwich cell revealed that the phase transition behaviour is affected by the presence of the nanoparticles and that the onset of the nematic phase is observed in the form of bubble-like domains whereas in the pure sample the nematic phase appears after the passing of a phase transition front. Transmission electron microscopy confirmed the presence of single nano-sized particles that were dispersed without forming aggregates in the material. The electro-optic properties of the nanoparticle-dispersed liquid crystal was investigated by measuring the threshold voltage for a twisted-nematic cell. The threshold voltage was found to depend on the frequency of the applied rectangular voltage, and at frequencies higher than 200 Hz, the threshold became lower than the pure samples.