Takeshi Yamao

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Temperature sensing to as low as 80 K was demonstrated with 1.55-μm fiber Bragg gratings. The gratings were bonded on substrates to increase sensitivity, and a shift of the reflection wavelength was measured. The temperature sensitivity was 0.02 nm/K at 100 K when an aluminum substrate was used and 0.04 nm/K at 100 K when a poly(methyl methacrylate)(More)
BACKGROUND The triple technique (lymphoscintigraphy, patent-blue staining, and a gamma probe) constitutes a reliable method for the sentinel lymph node (SLN) biopsy. However, in head and neck melanomas, a shine-through phenomenon, which occurs because these SLNs are close to the primary focus, is irreversibly problematic. To get around the shine-through(More)
Extremely high current densities are realized in single-crystal ambipolar light-emitting transistors using an electron-injection buffer layer and a current-confinement structure via laser etching. Moreover, a linear increase in the luminance was observed at current densities of up to 1 kA cm(-2) , which is an efficiency-preservation improvement of three(More)
IO N The ambipolar light-emitting transistor (LET) is a new type of electroluminescent device with the structure of an organic fi eldeffect transistor (OFET) with both hole and electron are transported. [ 1 ] Unlike the conventional organic light-emitting diodes (OLEDs), ambipolar LETs can move the emitting zone far away from the metal electrodes, which are(More)
We have improved performance of organic field-effect transistors (OFETs) composed of organic nanomolecular single crystals of a thiophene/phenylene co-oligomer. A poly(tetrafluoroethylene) thin layer was applied with friction-transfer technique to an insulator layer of silicon dioxide covering a silicon substrate. The crystals were grown in a liquid phase(More)
We report spectrally-narrowed emissions that take place from an organic semiconductor slab crystal of 2,5-bis(4-biphenylyl)thiophene (BP1T) under a low excitation-intensity regime. These emissions are caused with a mercury lamp that operates on a household power supply with an electric current approximately 1 A. The BP1T slab crystal is equipped with a(More)
Organic light-emitting transistors (OLETs) are of great research interest because they combine the advantage of the active channel of a transistor that can control the luminescence of an in-situ light-emitting diode in the same device. Here we report a novel single-crystal OLET (SCLET) that is coupled with single crystal optical feedback resonators. The(More)
The spectrally-narrowed emissions (SNEs) such as amplifi ed spontaneous emission are under intense investigation with organic semiconducting materials. [ 1 ] Although various experimental data relevant to SNEs have been accumulated through optically pumping the materials, there have thus far been very few examples of the SNEs attained on an electronic(More)
Autologous bone grafts remain the gold standard for the treatment of congenital craniofacial disorders; however, there are potential problems including donor site morbidity and limitations to the amount of bone that can be harvested. Recent studies suggest that granulocyte colony-stimulating factor (G-CSF) promotes fracture healing or osteogenesis. The(More)
[reaction: see text] Two derivatives of ethylenedioxy-substituted terthiophene-fullerene dyads were newly synthesized as the precursors for polythiophene having fullerene side chains. By electrolytic oxidation of dyad 1, the charm-bracelet type polythiophene, poly-1, was obtained as a purple film, which showed electrochemical activity, electrochromism, and(More)