In this paper, design and experimental results are described about a newly developed highly flexible fiber Faraday effect current sensor using the flint glass fiber as the sensor element. In the new type, a mirror is coated at an end of the flint glass fiber, and light takes round trip transmission in it. By the round trip transmission, the effect of rotation of polarization plane due to the torsion of the fiber is automatically canceled. Because of the low photo-elastic constant of the flint glass fiber, and the automatic canceling of the rotation, the polarization state of light passed through the fiber is stable. Therefore, in the new reflection type, it is not necessary to support the flint glass fiber with a durable circular frame to maintain accuracy. And so, the sensor head is small, light, and can be easily installed to existing power apparatus by winding the flint glass fiber around the current conductor without pulling out or cutting it. Experiments were done to verify the stable characteristics using the developed sensor model. In the experiments, relation between the final output signal of the sensor and shape of the curve of the flint glass fiber were examined. From the experiments, it became clear that the final output is almost perfectly independent on shape of the curve of the fiber. It was also confirmed that accuracy of the sensor conform to the standard of conventional current transducers for protection of power systems in Japan.

This paper reports on the development of an eyeglass-type infrared-controlled telephone communication interface for the disabled. This system is comprised of four major components: A) a headset; B) an infrared transmitting module; C) an infrared receiving/signal-processing module; and D) a main controller, the Intel-8951 microprocessor. The headset with a tongue-touch panel, a wireless earphone, and a wireless microphone. The infrared transmitting module utilizes a tongue touch panel via tongue-touch circuitry which is converted to an infrared beam and a low power laser (<0.1 mW) beam. The infrared receiving/signal-processing module, receives the infrared beam and fine tunes the unstable infrared beam into standard pulses which are used as control signals. The main controller is responsible for detecting the input signals from the infrared receiving/signal-processing module and verifying these signals with the mapping table in its memory. After the signal is verified, it is released to control the keys of the telephone interface. This design concept was mainly based on the idea that the use of an infrared remote module fastened to the eyeglasses could allow the convenient control of the dialing motion on the keys of a telephone's dialing-pad which are all modified with infrared receiving/signal-processing modules. The disabled are competent for some of work, such as a telephone operator. The increase of opportunity to do a job for the disabled would help them live independently.

A novel analog-computation system using quantum-dot spin glass is proposed. Analog computation is a processing method that solves a mathematical problem by applying an analogy of a physical system to the problem. A 2D array of quantum dots is constructed by mixing two-dot (antiferromagnetic interaction) and three-dot (ferromagnetic interaction) systems. The simulation results show that the array shows spin-glass-like behavior. We then mapped two combinatorial optimization problems onto the quantum-dot spin glasses, and found their optimal solutions. The results demonstrate that quantum-dot spin glass can perform analog computation and solve a complex mathematical problem.

We developed a glass ferrule fiber optic connector. During development, we also studied wear-resistant coating technology for preventing scratches on the surface of a glass ferrule. The method of coating was sputtering, and the material was alumina. We confirmed that a thin uniform coating could be formed on the ferrule surface to improve the durability of glass ferrule connectors.

I have examined factors for implementing a high-speed, low-power-consumption thermal head. In conventional thermal heads, a heat insulation layer is provided between the heating resistor and the radiator. I found it desirable to implement fast operation and low power consumption to lower the thermal conductivity of the heat insulation layer and to thin the heat insulation layer. I also found there is an optimum heat characteristic to the thickness of one heat insulation layer. I assumed polyimide as a material for the heat insulation layer which could materialize the hypothesis, and studied necessary items based on the thermal calculation. I manufactured a trial thermal head on the basis of this result and confirmed that our assumptions were correct. In addition, to confirm that the assumption is also ultimately correct, I fabricated a trial thermal head only consisting of a heating resistor and without a protective coat and a heat insulation layer. I confirmed that the structure with only the heating resistor exhibited excellent heat response and consumed less power necessary for heating.

A 3-dimensional specific thickness profile was fabricated on a thin glass diaphragm lens to reduce aberration at short focal distances for greater dynamic focusing. The deformation of the diaphragm was calculated by stress analysis utilizing the Finite Element Method (FEM). Geometric non linearity is considered in the FEM analysis. The glass diaphragm is 10 mm in diameter and the average thickness is 11 µm. To obtain both a curved shape and an optical surface on the glass diaphragm, the 3-dimensional precision grinding technique was utilized. The processed shape matches the designed one with less than 0.3 µm deviation, and the average surface roughness is 0.005 µm. Optical characteristics of the dynamic focusing lens having a specific thickness profile, were measured by Modulation Transfer Function (MTF) measurement equipment. At a focal distance of 250 mm, the specific thickness diaphragm lens resolution is 10 cycles/mm, whereas, the uniform thickness diaphragm is 4 cycles/mm. Even at other focal distances, the specific thickness diaphragm shows superior optical characteristics in comparison with those of the uniform thickness diaphragm. The 3-dimensional profile diaphragm resolution is 2.5 times finer at a focal distance of 250 mm, thus, being capable of displacement control for variable optic devices. This was achieved by employing semiconductor processing methods in conjunction with precision grinding techniques which are necessary for fabricating micro structures.

Nojima and Fujita have found a universal relation, irrespective of temperatures T, between the reduced field hH/Hir(T) and the reduced quantity of magnetization hysteresis mΔM (T, H)/ΔM (T, H0), where Hir is the irreversibility field and ΔM(T, H) is the hysteresis of magnetization for YBa2Cu3Ox and Bi2Sr2CaCu2Ox films. We could explain this universal relation based on a scaling theory in a three-dimensional superconducting vortex-glass phase. The exponent ν derived by this relation coincides with that obtained by nonlinear I-V characteristics for YBa2Cu3Ox films.

A glass precursor resist (GPR) is designed on the basis of an idea of conversion of organosilicon polymer to an inorganic substance by lithographic procedure. Developed chemical amplification resist system is composed of poly (di-t-butoxysiloxane) and a photoacid generator. It has a high sensitivity of 1.6 µC/cm2, a resolution of 0.2 µm and an extremely high O2-RIE durability compared with bottom resist. Exposed film changed into silicate glass, and it was confirmed by IR spectra.

We report on 1N branching devices for fiber-optic networks. A novel Y-pattern mask for loss reduction in branching waveguide has been investigated based on simulation. 18 branching waveguides fabricated by ion-exchange proved that the scattering loss at the branching region made with novel Y-pattern is reduced considerably. Pigtailing technique has been developed using glass fiber arrays (FAs). The fibers in FA are aligned precisely, so that all fibers can be easily and precisely put into alignment with the output ports in a branching waveguide chip at the same time. A glass plate is used for reinforcement which improves mechanical and thermal stability of the device. Reliability of packaged devices is being strongly demanded. Various reliability tests have been performed with packaged 18 branching devices and those results are presented.