Faculty Profiles - BENINO Yasuhiko

Papers - BENINO Yasuhiko

Division display 101 - 120 of about 141 ／ All the affair displays >>

Tsuyoshi Honma, Yasuhiko Benino, Takumi Fujiwara, Takayuki Komatsu, Ryuji Sato Reviewed

Applied Physics Letters

83 ( 14 ) 2796 - 2798 2003.10

Refractive index change induced by ultraviolet laser irradiations in erbium-doped tellurite glasses Reviewed

Fujiwara, I, Nakamoto, I, T Homna, Y Benino, T Komatsu

ELECTRONICS LETTERS 39 ( 22 ) 1576 - 1577 2003.10

Language：English Publishing type：Research paper (scientific journal) Publisher：IEE-INST ELEC ENG

A large change of refractive index, An, induced by ultraviolet excimer laser irradiations in Er2O3-doped tellurite-based glass, which is a promising material for fibre amplifiers, has been obtained. The value of Deltan/n larger than 5% was successfully achieved, and amplitude of Deltan depending on Er2O3-concentrations has been found.

DOI： 10.1049/el:20031031

Web of Science

researchmap

Elastic and mechanical properties of transparent nanocrystallized KNbGeO5 glass

F Torres, K Narita, Y Benino, T Fujiwara, T Komatsu

JOURNAL OF APPLIED PHYSICS 94 ( 8 ) 5265 - 5272 2003.10

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

KNbGeO5 (i.e., 25K(2)O-25Nb(2)O(5)-50GeO(2)) glass with the glass transition 622 degreesC and crystallization onset 668 degreesC temperatures shows prominent nanocrystallization, giving K3.8Nb5Ge3O20.4 nanocrystals with the size of similar to30 nm. Dielectric, elastic and mechanical properties of transparent nanocrystallized KNbGeO5 glasses are examined using some techniques such as polarizability analysis, cube resonance spectra and Vickers nanoindentation. Electronic polarizability, shear modulus, bulk modulus, Young's modulus (E), Debye temperature (theta(D)), Vickers hardness, and deformation energies during nanoindentation increase largely due to the nanocrystallization, e.g., E=64.1 GPa and theta(D)=500 K for the base glass and E=85.5 GPa and theta(D)=575 K for a transparent nanocrystallized glass. The values of Poisson's ratio and fractal bond connectivity of nanocrystallized glasses are the same as those of the base glass, suggesting that relative arrangements of constituent ions (K+, Nb5+, Ge4+) in nanocrystallized glasses are basically similar to those in the base glass. The present study suggests that nanocrystallization in glass results in not only more compact atomic arrangements but also in an increase in interatomic strength. (C) 2003 American Institute of Physics.

DOI： 10.1063/1.1609641

Web of Science

researchmap

Shingo Kawasaki, Tsuyoshi Honma, Yasuhiko Benino, Takumi Fujiwara, Ryuji Sato, Takayuki Komatsu Reviewed

Elsevier 325 ( 1-3 ) 61 - 69 2003.7

YAG laser-induced beta-BaB2O4 crystalline dot formation in Sm2O3-BaO-B2O3 glasses Reviewed

H Tanaka, T Honma, Y Benino, T Fujiwara, T Komatsu

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS 64 ( 7 ) 1179 - 1184 2003.7

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

A continuous-wave (CW) YAG laser (power: 0.75-0.9 J/s, irradiation time: 15 s-15 min) with a wavelength of 1064 nm is irradiated to 11.1Sm(2)O(3).44.4BaO.44.4B(2)O(3) glass, and the formation of beta-BaB2O4 (beta-BBO) crystalline dots with a diameter of 30-150 mum is confirmed from micro-Raman spectra. beta-BBO crystals with around 200 mum length grow towards the interior of the glass. The incorporation of Sm3+ into beta-BBO crystalline dots is suggested from micro-Raman and fluorescence spectra. The second harmonic generation is detected from the array (10 x 10 = 100 dots) of beta-BBO crystalline dots, indicating that each crystalline dot formed by YAG laser irradiation is a nonlinear optical crystal. CW YAG laser irradiation to glass with Sm3+ ions is a nice technique for a spatially controlled crystal growth. (C) 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0022-3697(03)00047-7

Web of Science

researchmap

Direct observation of second-harmonic generation from crystalline particles in Ge-doped SiO2 glass films Reviewed

T Fujiwara, T Sawada, Y Benino, T Komatsu, M Takahashi, T Yoko, J Nishii

OPTICS EXPRESS 11 ( 14 ) 1598 - 1606 2003.7

Language：English Publishing type：Research paper (scientific journal) Publisher：OPTICAL SOC AMER

The authors report what is, to our best knowledge, the first observation of second-harmonic generation (SHG) directly from the crystalline particles in Ge-doped SiO2 (Ge:SiO2) glass films. Ge:SiO2 glass films with approximately 5 mum thickness were fabricated by chemical vapor-phase deposition. X-ray diffraction ( XRD) peaks at around 2theta=22degrees in thermally crystallized Ge:SiO2 films were observed, and obtained XRD patterns are exactly the same as those in ultraviolet-laser-poled Ge: SiO2 glasses. Using SHG microscopic technique with a Nd:YAG laser, it has been successfully found that SH emitting with 532 nm wavelength is observed directly from the crystalline particles induced in the crystallized films. (C) 2003 Optical Society of America.

DOI： 10.1364/OE.11.001598

Web of Science

researchmap

Evolution and characterization of fluorite-like nano-SrBi2Nb2O9 phase in the SrO-Bi2O3-Nb2O5-Li2B4O7 glass system Reviewed

N. S. Prasad, K. B. R. Varma, Y. Takahashi, Y. Benino, T. Fujiwara, T. Komatsu

Journal of Solid State Chemistry 173 ( 1 ) 209 - 215 2003.6

Crystalline phases and second harmonic intensities in potassium niobium silicate crystallized glasses Reviewed

H. Tanaka, M. Yamamoto, Y. Takahashi, Y. Benino, T. Fujiwara, T. Komatsu

Optical Materials 22 ( 1 ) 71 - 79 2003.3

Thermal poling of transparent TeO2-based nanocrystallized glasses and enhanced second harmonic generation

N Tamagawa, Y Benino, T Fujiwara, T Komatsu

OPTICS COMMUNICATIONS 217 ( 1-6 ) 387 - 394 2003.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A transparent TeO2-based nanocrystallized (crystalline particle size: similar to40 nm) glass (composition: 15K(2)O . 15Nb(2)O(5). 68TeO(2) . 2MoO(3)) showing a second harmonic generation (SHG) has been prepared, and a thermal poling has been applied to examine whether a poling technique is effective in enhancing the SH intensity of nanocrystallized glass. In the poling condition of 2.0 kV (DC voltage), 210 degreesC and 40 min, the SH intensity of nanocrystallized glass is enhanced, demonstrating that a combination of nanocrystallization and thermal poling is an useful technique to induce a SHG in glass. As similar to the case of glass, a prominent SHG is observed at the anode side in the thermal poling, suggesting the increase in polarization in nanocrystals. (C) 2003 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0030-4018(02)02356-8

Web of Science

researchmap

Universal hardness and elastic recovery in Vickers nanoindentation of copper phosphate and silicate glasses

T. Miura, Y. Benino, R. Sato, T. Komatsu

Journal of the European Ceramic Society 23 ( 3 ) 409 - 416 2003.3

Language：English Publishing type：Research paper (scientific journal)

Load/unload displacement (penetration) curves for yCuOx·(100-y)P2O5 glasses (y=45, 50) with different copper valence states, silica and soda-lime silicate glasses at room temperature (humidity ∼64%) have been measured using a Vickers nanoindentation technique, and universal hardness Hu and elastic recovery ER have been estimated in the load range of 0.1-1 N. Copper phosphate glasses have the values of Hu=1.7-2.5 GPa and ER=0.55=0.65, depending on the Cu+/Cu2+ ratio. The glasses with high Cu+ contents show large densifications (plastic deformation) during loading and small elastic recoveries during unloading compared with the glasses with no Cu+ ions. These deformation behaviors are well explained qualitatively by considering lower coordination number and more covalent bonding of Cu+ compared with Cu2+, which have been confirmed from X-ray photoelecton spectra. Silica glass has ER≒0.77, which is large compared with ER≒0.63 in a soda-lime silicate glass. This large difference leads to the smaller value in Hu of silica glass than that of a soda-lime silica glass. It is confirmed that load displacement curves in nanoindentation tests are well fitted with quadratic equations. © 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0955-2219(02)00154-1

Scopus

researchmap

Formation mechanism of ferroelastic Ba2TiGe2O8 and second order optical nonlinearity in transparent crystallized glasses Reviewed

Y. Takahashi, Y. Benino, T. Fujiwara, T. Komastu

Journal of Non-Crystalline Solids 316 ( 2-3 ) 320 - 330 2003.2

Formation of gratings and two-dimensional photonic structures by laser-induced nano-crystallization

T Fujiwara, R Ogawa, Y Benino, T Komatsu, J Nishii

INTERNATIONAL SYMPOSIUM ON PHOTONIC GLASS (ISPG 2002) 5061 114 - 122 2003

Language：English Publishing type：Research paper (international conference proceedings) Publisher：SPIE-INT SOC OPTICAL ENGINEERING

We propose and demonstrate gratings and two-dimensional (2D) photonic structure of nanometer-scale crystals/particles in glass surface created by one of the most simple way ever reported. Grating structures consisting of nanocrystals have been fabricated on surface of tellurite-based glasses, with a composition of 15K(2)O-15Nb(2)O(5)-70TeO(2) (mol%), using photoinduced nano-crystallization. A conventional phase mask technique was performed for the grating fabrication with a XeCl excimer laser operating at 308 nm. Periodic structure with 400 nm pitch constructed by lines of regularly ordered nanoparticles having a diameter up to about 100 nm was confirmed by atomic force microscopy and scanning electron microscopy. It is strongly suggested from measurement of X-ray diffraction that the photoinduced nanoparticles have a crystalline phase, and also suggested from measurement of optical frequency doubling that the periodic nanoparticle structure exhibits second harmonic generation (SHG) with an unique polarization dependence of SHG based on nano-structures of dielectric polarization. In addition, such a simple method of phase mask usage was applied to formation of 2D array, and the 2D structures of nano-particles/holes were. successfully obtained by laser irradiations.

Web of Science

researchmap

Tsuyoshi Honma, Yasuhiko Benino, Takumi Fujiwara, Takayuki Komatsu, Ryuji Sato Reviewed

Applied Physics Letters

Applied Physics Letters 82 ( 6 ) 892 - 894 2002.12

Second-order optical nonlinearity of LaBGeO5, LiBGeO4 and Ba2TiGe2O8 crystals in corresponding crystallized glasses Reviewed

Y Takahashi, Y Benino, T Fujiwara, T Komatsu

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS 41 ( 12B ) L1455 - L1458 2002.12

Language：English Publishing type：Research paper (scientific journal) Publisher：INST PURE APPLIED PHYSICS

Second-order optical nonlinearities, d(33), of LaBGeO5, LiBGeO4 and Ba2TiGe2O8 crystals in transparent crystallized glasses were estimated by means of the Maker fringe technique. Transparent surface crystallized glasses were fabricated by crystallization of a glass with the exact or close stoichiometric composition of each crystal. The d(33) values of similar to0.13 pm/V for LaBGeO5, similar to0.7 pm/V for LiBGeO4 and similar to7 pm/V for Ba2TiGe2O8 crystals were obtained. The crystallized glass consisting of Ba2TiGe2O8 crystals with pyramidal TiO5 units has the largest d(33) value of the crystallized glasses reported so far, and its value is comparable to the d(22) value of LiNbO3 single crystal. It is proposed that LiBGeO4 and Ba2TiGe2O8 crystals can be considered as new candidates for optical nonlinear crystals.

DOI： 10.1143/JJAP.41.L1455

Web of Science

researchmap

Optical second order nonlinearity of transparent Ba2TiGe2O8 crystallized glasses Reviewed

Y. Takahashi, Y. Benino, T. Fujiwara, T. Komatsu

Applied Physics Letters 81 ( 2 ) 223 - 225 2002.7

Ferroelectric properties and second harmonic intensities of stillwellite-type (La,Ln)BGeO5 crystallized glasses

Y Takahashi, A Iwasaki, Y Benino, T Fujiwara, T Komatsu

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS 41 ( 6A ) 3771 - 3777 2002.6

Language：English Publishing type：Research paper (scientific journal) Publisher：INST PURE APPLIED PHYSICS

Glasses with compositions corresponding to stillwellite-type (La,Ln)BGeO5 (Ln: Nd, Gd, Eu and Tin) crystalline phases hake been prepared, and the effect of lanthanide substitution,., on ferroelectric properties and second harmonic (SH) intensities of stillwellite-type crystalline phases formed by crystallization of glasses has been examined, The substitution of Ln(3+) for La3+ ions in the LaBGeO5 phase has been confirmed from the results of X-ray diffraction (XRD) analysis and fluorescence spectra of Eu3+ ions. The substitution of Ln(3+) for La3+, ions causes a decrease not only in the lattice constants but also in the a/c axis ratio. The amount of substitutions depends on the Ln(3+) I ionic radius. The Curie temperature of crystallized glasses increases almost linearly with decreasing mean ionic radius of lanthanides estimated from the composition of base glasses. A similar trend is observed in the SH intensity for crystallized glasses (powdered form). indicating the presence of a close relationship between Curie temperature and SH intensity. It is proposed from Raman spectra that the enhancement of SH intensities is caused by the change in the arrangements of BO4 and GeO4 tetrahedra in the (La,Ln)BGeO5 crystals due to the substitution of Ln(3+) ions having stronger Ln(3+)-O bonds. A clear second harmonic generation is observed in transparent surface crystallized glasses of the Nd2O3- or Gd2O3-substituted system.

DOI： 10.1143/JJAP.41.3771

Web of Science

CiNii Article

researchmap

Tsuyoshi Honma, Yasuhiko Benino, Takumi Fujiwara, Ryuji Sato, Takayuki Komatsu Reviewed

Optical Materials

Optical Materials 20 ( 1 ) 27 - 33 2002.3

Electronic polarizability, optical basicity, and interaction parameter of La2O3 and related glasses Reviewed

T Honma, Y Benino, T Fujiwara, T Komatsu, R Sato, Dimitrov, V

JOURNAL OF APPLIED PHYSICS 91 ( 5 ) 2942 - 2950 2002.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER INST PHYSICS

The electronic polarizability and optical basicity of La2O3 and related glasses have been determined from ultraviolet absorption spectra and calculations based on the Lorentz-Lorenz equation. The optical basicity for La2O3 oxide is found to be 1.07, being much larger compared with typical glass-forming oxides such as B2O3 (0.42) and SiO2 (0.48) but being similar to heavy element oxides such as TeO2 (0.93). The Yamashita and Kurosawa's interaction parameter of La2O3 is 0.03 A(-3), indicating that La2O3 is classified as a normal ionic (basic) oxide, i.e., an ionic bonding character in the La3+-O bond is proposed. Close correlations are confirmed among optical basicity, interaction parameter, and oxygen 1s binding energy in x-ray photoelectron (XPS) spectra for La2O3-P2O5 and other La2O3-containing glasses. It is found from XPS and Raman spectra that La3+ ions in La2O3-P2O5 glasses act as network modifiers, supporting an ionic bonding character in the La3+-O bond. The parameters related to electronic polarizability in La2O3 determined in the present study would be useful for the design of rare-earth containing optical functional glasses. (C) 2002 American Institute of Physics.

DOI： 10.1063/1.1436292

Web of Science

researchmap

Correlation among electronic polarisability, optical basicity, interaction parameter and XPS spectra of Bi2O3-B2O3 glasses Reviewed

T Honma, Y Benino, T Komatsu, R Sato, Dimitrov, V

PHYSICS AND CHEMISTRY OF GLASSES 43 ( 1 ) 32 - 40 2002.2

Language：English Publishing type：Research paper (scientific journal) Publisher：SOC GLASS TECHNOLOGY

The average electronic polarisability of the oxide ion (alpha(O2-)), optical basicity (Lambda),Yamashita Kurosawa's interaction parameter (A) and oxygen 1s (O1s) binding energy in x-ray photoelectron spectroscopy (XPS) of xBi(2)O(3) (100-x) B2O3 glasses (x=0similar to65) have been examined to check correlations among them and to clarify the electronic structure of the glasses and bonding character of Bi O. Both alpha(O2-) and Lambda increase gradually with increasing Bi2O3 content. and large alpha(O2) values over 2 A(3) and large Lambda values over 0.9 are obtained in the glasses with high Bi-O contents. The interaction parameter ranges from about 0.05 to 0.25 and decreases with increasing Bi2O3 content. The Ols peak in XPS spectra consists of two components: the Ols peak with higher binding energies. O1s(1), is assigned to B O-B bonds and that with lower binding energies O1s(2), correspond to Bi-O-B and Bi-O-Bi bonds. The O1s(1) binding energy decreases gradually with increasing, Bi2O3 content but the O1s(2) binding energy is almost constant suggesting that the ionic/covalent character of Bi-O bonds does not change significantly with composition. Close correlations are observed among alpha(O2-). A A and mean O1s binding energy. Particularly, it has been found that O1S binding energy is a good measure of the optical basicity of Bi2O3-B2O3 glasses and the interaction parameter gives good information about the electronic polarisability of oxide glasses as well as optical basicity. It is found that Bi-O bounds in Bi2O3-B2O3 glasses are more ionic compared with Sb O bonds in Sb2O3 B2O3 glasses.

Web of Science

researchmap

New Transparent Crystallized Glasses with Optical Nonlinear LiBgeO_4 Crystals

TAKAHASHI Yoshihiro, BENINO Yasuhiko, FUJIWARA Takumi, VARMA Kalidini B.R., KOMATSU Takayuki

Journal of the Ceramic Society of Japan 110 ( 1277 ) 22 - 26 2002.1

Language：English Publisher：The Ceramic Society of Japan

Crystallization behaviors of the glass with a composition of 25Li_2O・25B_2O_3・50GeO_2 corresponding to lithium borogermanate LiBGeO_4 have been examined. It has been confirmed that the LiBGeO_4 crystalline phase is formed at the surface of heat-treated glasses. The second harmonic(SH)generation is found from transparent surface crystallized glasses, demonstrating for the first time that the LiBGeO_4 phase shows optical nonlinearity. The SH intensity of LiBGeO_4 crystallites(powdered state)prepared through crystallization is about ten times as large as that of pulverized α-quartz. The SH intensity of transparent crystallized glasses(bulk state)with crystalline layers of 3-4.5 μm thickness increases with increasing heat treatment temperature(540-560℃)and time(1-6 h), and the maximum SH intensity among the samples studied is in the order of 1/10 in comparison with that of α-quartz single crystal. The transparent crystallized glass obtained by heat treatment at 550℃ for 3 h exhibits a clear and fine Maker fringe pattern, indicating a highly orientation of LiBGeO_4 crystals at the surface.

DOI： 10.2109/jcersj.110.22

CiNii Article

CiNii Books

researchmap

Other Link： https://jlc.jst.go.jp/DN/JALC/00155090284?from=CiNii

　 PREV - NEXT 　

< BENINO Yasuhiko >

Papers - BENINO Yasuhiko