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ABSTRACT: ErSiO superlattice crystal (SC) waveguide is demonstrated. ErSiO-SC film was formed on a SiO2/Si substrate. After the ErSiO preform formation by sol–gel method, high temperature anneal for the crystallization was performed in Ar atmosphere. Then the ErSiO-SC layer thickness is 220 nm. Then refractive index of ErSiO-SC was estimated to be 1.8 by ellipsometry and reflection spectroscopy measurements. To obtain the lateral optical confinement, polymer cladding layer (n = 1.54) was coated on the ErSiO-SC film and the strip-loaded structures with 5 μm width were formed by focused ion beam (FIB) etching. The optical confinement factor Γ of the ErSiO-SC waveguide layer was estimated to be 0.42, assuming the lateral confinement factor was 1 because of the sufficient wide waveguide for the light. Optical pumping was performed by using a 1480 nm laser diode through the lensed fiber. The pumping power is 30 mW at the fiber input. Green light emissions corresponding to 4f intra-shell transitions from 4S3/2 and 2H11/2 to 4I15/2 in the Er3+ ions, indicating cooperative upconversion in the ErSiO-SC waveguide, can be observed by using a conventional CCD system at room temperature. The upconversion emission behaviour through the waveguide with a photon trap for the 1480 nm light reveals that the 1480 nm pumping light is well-confined into the waveguide. The cooperative upconversion as the gain limitting factor in the ErSiO-SC waveguide are discussed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Physica Status Solidi (A) Applications and Materials 12/2007; 205(1):52 - 55. · 1.46 Impact Factor
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ABSTRACT: This paper presents the relation between the partial pressures and growth rate on forming Er-Si-O crystalline thin films used by MOMBE.
Group IV Photonics, 2007 4th IEEE International Conference on; 10/2007
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ABSTRACT: Semiconducting nature of ErSiO crystalline compounds with superlattice structure is revealed by photocurrent excitation (PCE) and Photoluminescence excitation (PLE) measurement.
Group IV Photonics, 2005. 2nd IEEE International Conference on; 10/2005
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ABSTRACT: We present a case of a gradually developing ischaemic contracture of the forearm muscles of an infant who developed without any trauma or acute gangrene at birth. Release of the middle and ring finger digitorum profundus muscles and pronator quadratus at 2 years of age corrected the deformity. Histopathology showed no evidence of fibromatosis or any other tumor. Although a dynamic splint was used to maintain the range of motion, the range of the middle finger motion deteriorated gradually 2 years after surgery. Though the pathogenesis of this problem was unclear, we assume that it was caused by fibrosis of muscles as a result of bleeding before or during delivery.
The Journal of Hand Surgery British & European Volume 11/2004; 29(5):510-3. · 0.04 Impact Factor
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ABSTRACT: MgxZn1–xO thin film alloys were formed on Si substrates by a sol–gel method. The percentage of Mg was controlled by the mol ratio in the starting alcoholate sol solution. The structure of films was studied by X-ray diffraction (XRD). The grain morphology and their spatial compositions were measured by scanning electron microscopy (SEM) together with energy dispersive X-ray spectrometry (EDS) analysis. The films were found to be composed of grains of around several ten nanometers in size and different Mg contents. The photoluminescence (PL) shows a bandedge emission with its peak energy changing from 3.3 eV to 3.6 eV for the Mg content of the starting alcoholate solution from 0% to 20%. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
physica status solidi (c) 09/2004; 1(10):2564 - 2568.
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ABSTRACT: We present a rare case of a lateral dislocation of the proximal interphalangeal joint that required open reduction. During an operation, we found the collateral ligament and the capsule interposing into the joint space. After reducing the soft tissue and reproducing the collateral ligament with a suture anchor, sufficient joint stability and full range of motion was achieved.
Hand Surgery 08/2004; 9(1):131-5.
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ABSTRACT: Ge dot formation on Si(100) in metal organic vapor phase epitaxy (MOVPE) using tetramethylgermanium (TMGe) as the Ge source is demonstrated. The dots were formed in the growth temperature range between 600 and 700 °C. Atomic force microscopy measurement indicates that Ge dots grow in the Stranski–Krastanov mode. By comparison of the aspect ratio of the dots to those obtained by other growth methods, it is shown that the Ge dot formation mechanism and the resulting dot shape depend on the atmosphere during the dot formation.
physica status solidi (c) 07/2003;
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ABSTRACT: Time-resolved excitation and relaxation processes of the impact excitation emission (EL) at 1.54μm of Er3+ ions doped in InP were investigated in the temperature range from 77K to 330K. The decay process was almost exponential in all the measured temperature range and showed little thermal quenching. The decay time of 2ms at 77K decreased only to tms at 330K. This result contrasted with the large thermal quenching and nonexponential characteristics of the photoluminescence (PL) time decay at higher temperatures, suggesting different Er3+ centers excited between EL and PL. A two-emission-center model is proposed and the different behaviors of thermal quenching and time decay between EL and PL emissions are consistently explained.
MRS Proceedings. 12/1992; 301.
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ABSTRACT: A high performance liquid chromatographic method for measuring vitamin K in human milk and cow milk is described. The K vitamins were extracted with n-pentane from enzymatic hydrolysate of milk, purified by semipreparative HPLC, and then analyzed by reversed-phase HPLC equipped with a dual electrochemical detector. The amount of phylloquinone and menaquinone-4 in human milk was 2.1 +/- .9 and 1.3 +/- 1 microgram/L, respectively (n = 23). A small amount of menaquinone-6 was detected in both human and cow milk.
Journal of Dairy Science 04/1988; 71(3):627-32. · 2.56 Impact Factor
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ABSTRACT: This paper presents strong and sharp Er-related 1.53 μm photoluminescence characteristics and crystalline properties of Er-Si-O thin films formed by sol-gel method.
Group IV Photonics, 2004. First IEEE International Conference on;
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ABSTRACT: Er-related 1.5 μm emissions with linewidth of less than 1 meV and 10 μs lifetime have been observed in crystalline ErSiO superstructures.
Group IV Photonics, 2004. First IEEE International Conference on;
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ABSTRACT: Er–Si–O crystalline thin film preparation on silicon substrates by using metal organic molecular beam epitaxy (MOMBE) is proposed. Tetra ethoxy silane (TEOS) and tris-2,2,6,6-tetra methyl-3,5-octane dionato erbium (Er(TMOD)3) were used as Si–O and Er–O precursors, respectively. The Er–Si–O thin film crystallizes mainly during the post-annealing process and into a novel type of erbium-silicate crystalline compounds, which have not ever been reported. The atomic fraction of Er:Si:O in the prepared thin film is 3:2:8. The Er3+ related PL spectra show a fine structure with a line width of less than 1 meV at 20 K and 4 meV at room temperature. The narrow line width is due to the crystalline nature. In addition, the PL spectrum fine structure observed in these Er–Si–O films has reproduced the fine structure observed in Er–Si–O crystallites prepared by the wet-chemical method reported by Isshiki et al. The present results have proved that the method proposed in this paper is effective to form Er–Si–O crystalline films.
Optical Materials.
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ABSTRACT: ErSiO crystalline compounds such as erbium silicates (Er2Si2O7 and Er2SiO5) and Er2O3 have been attracting attention as the new light source material for silicon photonics. In our previous reports, several results indicated that the ErSiO crystalline compound was non-stoichiometry (Er:Si:O=1:2:2.4) and showed carrier mediated excitation. In our later study, however, it has been found the ErSiO crystalline compound contains Er2SiO5 (PDF#52-1809) crystalline matrix. ErSiO compounds made from the sol–gel solution of Er:Si=1:2 and Er:Si=2:1 show that the X-ray diffraction (XRD) peak patterns are in good agreement with the Er2SiO5. Rutherford back scattering (RBS) and secondary ion mass spectrometry (SIMS) results for the ErSiO compounds also show phase separation of Er2SiO5 and SiO2. SiO2-rich Er2O3–SiO2 systems usually show phase separation of Er2Si2O7 and SiO2 but this system behaves in a different manner. Furthermore, bulk Er2SiO5 emits light only by direct excitation of Er. From PL excitation (PLE) measurements, the indirect excitation emission observed in the Si-rich non-stoichiometric ErSiO compound is considered due to Er2SiO5 crystallites embedded in SiOx, which can be formed by the phase separation.
Physica E: Low-dimensional Systems and Nanostructures.
