Large electro-optic effects of liquid-crystal materials are attractive in applications to various optical devices in a wider wavelength region. Fundamental optical properties in the submillimeter wave region, such as refractive indices and transmission losses for some cyanobiphenyl nematic liquid crystals, have been investigated for the first time, to our knowledge, with a submillimeter laser. Refractive indices of the liquid crystal materials for ordinary and extraordinary rays are a little larger than those in the visible region, and a larger birefringence comparable with the visible region can also be obtained. Although the loss level is larger by ~2 orders of magnitude than that of quartz plate, which is an excellent window in the submillimeter wave region, the transmission of the liquid crystal cell is high enough.

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This letter reports the microfabrication, evaluation, and application of a boron-doped diamond microprobe with an integrated resistive heater element. The diamond heater with a pyramidal tip, which is formed at the end of two diamond beams, can be electrically heated by a flowing current. The high thermal conductivity of the diamond base supporting the heater element allows very quick thermal response of 0.45 μs. A hard-wearing sharp diamond tip formed by the silicon-lost mold technique shows excellent durability in contact operation with a sample. Diamond is well suited to use as a nanolithography tool for modification of a polymer, because polymer is hard to deposit on the tip during scanning due to the chemical inertness of the diamond surface. Demonstration of thermomechanical nanolithography with this heated probe exhibits line patterns with the feature size of 40 nm on a poly(methylmethacrylate) film.

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Scanning near-field optical microscopy using a slit-type probe is discussed. The slit-type probe has a width of much less than a wavelength, λ, and a length on the order of λ, and thus has high transmission efficiency. Two dimensional near-field images of objects have been constructed using an image reconstruction algorithm based on computerized tomographic imaging. Experiments performed at 60 GHz (λ=5 mm) show that this type of near-field microscopy can achieve a spatial resolution of better than λ/45 for two dimensional imaging. A method for fabricating a submicron width slit probe at the end of an optical fiber is presented for extending this microscopy to optical waves.

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The photoluminescence properties and quantum efficiency of potential red, green, and blue (RGB) phosphors are measured under near-ultraviolet excitation (380–420 nm). The suitability of several phosphors is discussed for their application in phosphor-liquid crystal displays (LCDs). K5Eu2.5(WO4)6.25, SrGa2S4:Eu, and BaMgAl10O17:Eu phosphors are chosen as RGB phosphors for making a phosphor-LCD prototype. The color coordinates and optical properties of phosphor-LCDs are compared to those of conventional LCDs.