Buried-type optical waveguide with blanches for the gate of optical signals was fabricated by nano ion-exchange method
using the probe of atomic force microscope (AFM) as an electrode. 2-step procedure of the electric field-assisted Ag/Na-ion
exchange followed by K/Na one was applied to prepare the waveguide structure inside the glass substrate. Pt-coated
AFM probe as a cathode was attached to the glass surface and Ag<sup>+</sup> ions in the core underneath the probe were partially
extracted towards the glass surface. The protruding high index regions from the core towards the glass surface were
found to work as the optical gate where the wavelength and intensity of light through the gate was determined by the
condition of nano ion-exchange treatment.
Organic-Inorganic hybrid pillar arrays have been controlled by cohesive force during drying in photolithography.
Two-dimensional periodic pillars with micrometer repetitions were fabricated from an organic-inorganic hybrid
material. The pillars were gathered at the top and gtop-gatheringh pillar patterns were obtained depending on
pillar sizes such as height of the pillars and distance between neighboring pillars and types of rinse liquids. The
top-gathering pillar patterns could be obtained easily in the pillar arrays with same structural parameters using
1-PrOH as a rinse liquid rather than water. From in situ observation of the drying rinse liquids, it was found
that the drying of 1-PrOH differs from that of water in the pillar arrays because of the difference in the contact
angles. Top-gathering pillars were partially introduced in a homogeneous periodic pillar array by the different
pillar formations between two types of rinse liquids.
Multi-beam laser interference (MLI) lithography is known to be one of the fabrication techniques of photonic crystals. In MLI lithography, laser beams are interfered on a scale of the wavelength of light and are irradiated to photosensitive films. We have paid attention to photosensitive TiO2-organic hybrid film, which has high refractive index. TiO2-organic hybrid periodic pillar patterns were fabricated by MLI lithography. The TiO2 hybrid film, which was prepared from Ti-alkoxide and β-diketone by the sol-gel method, was exposed to the interference pattern of femtosecond pulses at 800 nm wavelength. After laser irradiation, the unirradated portion was removed by the development and rinse. Two-dimensional periodic standing alone pillars and 2×2 and 3×3 top-gathering pillars, which were gathered at the top by means of self-organization were formed by changing conditions such as laser irradiation time and film thickness. The pillar patterns depended upon the rinse liquid, the diameter, and the height of pillars. The top-gathering pillars are applicable for diffractive optics.
Capillary Electrophoresis Doping (CED) technique is proposed for the new doping technique of the functional molecules into the hybrid materials. Organic-inorganic hybrid films or waveguides are fabricated on the cathode and the capillary tube bridge is made between the hybrid materials and the anode solution bath. The capillary and the anode bath are filled with the solution of the functional molecules and DC voltage is applied between cathode electrode and the anode one. The functional molecules (ions) move along the electric field, and their doping into the hybrid materials
can be attained by the control of the capillary position and the electric current through the circuit. In this study, siloxane based hybrid films and waveguides are prepared, and the doping of organic laser dyes, Rhodamine6G and Cresyl violet are demonstrated using SiO<sub>2</sub> glass capillaries. It is shown that CED technique has a great potential to fabricate the multifunctional optical devices in which various different functional chemicals are contained.