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SMES of the 10 MVA for the power control in power system has been manufactured, and connected to a real power grid. In addition, innovative basic researches, for example, low cost converter, maintenance-free cryo-coolers, inter-locks system and so on, have also been developed. The SMES was installed in the metal rolling factory with hydro power plant. Field test has been carried out for load fluctuation compensation. SMES was able to compensate for the active power according to the fluctuating load, and confirm the situation with a smooth load change of 11 kV bus of hydro power stations. In this paper, field test results will be presented. [ABSTRACT FROM AUTHOR]

Single crystals of LuAG doped with Pr3+ ions (0.2 mol%) are grown by the micro-pulling-down (μ-PD) method with an RF heating system. The as-grown crystals are confirmed to be of garnet-type structure with the space group of Ia3d (230). The emission-excitation spectra and luminescence decay kinetics are measured in the temperature range of 5-310 K by using synchrotron radiation as an exciting light source. The intrinsic luminescence is observed at 250 nm at low temperatures. Four emission bands at 308, 325, 360, and 380 nm are ascribed to the 5d- > 4f transitions of Pr 3+ ions. From the decay kinetics measurements, it is pointed out that there exist two kinds of energy transfer mechanisms from the host LuAG lattice to the Pr 3+ ions. The mechanisms of energy transfer are discussed in connection with the formation of substitution-type defects. [ABSTRACT FROM AUTHOR]

CeF3 single crystals heavily doped with Sr2+ ions are grown by the micro-pulling-down (μ-PD) method. The deviation of the composition in as-grown crystals is found to be entirely negligible. Three dimensional emission-excitation spectra are measured in a wide temperature range of 5-300 K by using synchrotron radiation as an exciting light source. Two intense emission bands are observed at around 320 and 400 nm. The origin of these bands is discussed on the basis of the perturbation effects introduced by Sr doping. It is pointed out that the energy transfer takes place from Ce3+ sites to defect sites when the crystal is warmed from 5 to 300 K. [ABSTRACT FROM AUTHOR]

Hollow optical fiber probes are used for remote Raman and infrared spectroscopy. Preliminary experiments using these probes are performed, and the results of the experiments show that the hollow fiber probes are useful for endoscopic measurement of Raman and infrared spectroscopy. As regards to Raman spectroscopy, a hollow fiber probe with a ball lens at the end works as a confocal system. It can, thus, detect the molecular structure of biotissues with a high SNR. Owing to their small diameter, the probes are useful for in vivo noninvasive analysis by using a flexible endoscope. A hollow-fiber probe was also used for remote Fourier transform infrared spectroscopy in the form of an endoscopic measurement of infrared reflectometry spectra inside the body. This measurement was made possible by the high flexibility and durability, nontoxicity, and low transmission losses of the hollow-fiber-based probes. [ABSTRACT FROM PUBLISHER]

Silica-core Bragg fibers supporting the single HE11 mode are proposed for fiber devices including compact nonlinear devices and dispersion control components. Fibers are fabricated by forming a dielectric multilayer on the outside of a conventional single-mode fiber, which is partly redrawn to a small diameter. Bragg guidance over a broadband wavelength range and the mode profile that corresponds with the HE11 mode are observed [ABSTRACT FROM PUBLISHER]

When fibers are clamped together between two fiber-holding substrates and butt-joined, variations in the fabrication accuracy of both fibers and substrates usually result in the fibers experiencing different clamping forces. If, for example, a couple of fibers are undersized or the substrate surface is deformed, the clamping force will be insufficient in places. In such cases, the fibers will leave only faint linear marks on the substrate surface and may slip when internal or external forces act on them. By using Hertz's theory, we converted the resistance force to fiber slippage into a line width curve for the onset of slippage. We spliced single fibers with known outer diameters to examine the influence of line width on slippage. We performed a fiber retention test, a temperature cycling test to determine any insertion loss change, and observed the linear marks with a microscope. No fiber slippage occurred when the width of the linear marks was outside the line width curve. Furthermore, we calculated the core-axis offset probability distribution when the optical fiber axes were aligned [ABSTRACT FROM PUBLISHER]

In mechanical splice technology, one of the basic problems is the slippage between fibers and fiber-holding substrates. We analyzed the relationship between the dimensions and material constants of a splice in a fiber butt-joint region and the force distributions along fibers, when external tensile forces or thermal stress acted on the fiber joint region. We evaluated factors relating to the slippage and these effects quantitatively. We then designed the joint region largely based on this analysis. We confirmed the joint characteristics using a temperature cycling test in accordance with the relevant Telcordia Technologies (formerly Bellcore) test specification and microscope observations of the damage to the fiber ends after the test. We achieved a highly stable mechanical splice for single fibers and four-fiber ribbons with an insertion loss change of less than ±0.1 dB during the test and with no damage to the fiber ends [ABSTRACT FROM PUBLISHER]

CeF3 single crystals heavily doped with Sr2+ ions are grown by the micro-pulling-down (μ-PD) method. The deviation of the composition in as-grown crystals is found to be entirely negligible. Three dimensional emission-excitation spectra are measured in a wide temperature range of 5-300 K by using synchrotron radiation as an exciting light source. Two intense emission bands are observed at around 320 and 400 nm. The origin of these bands is discussed on the basis of the perturbation effects introduced by Sr doping. It is pointed out that the energy transfer takes place from Ce3+ sites to defect sites when the crystal is warmed from 5 to 300 K. [ABSTRACT FROM AUTHOR]