Search Results:　 1-20 of 641

  • 1

    Dual-Polarization DWDM/DQPSK Optical Packet Switching and Field Trial  [in Japanese]

    SHINADA Satoshi , FURUKAWA Hideaki , WADA Naoya

    … 電気光学効果光スイッチを用いて構成された光パケットスイッチの処理特性は,光スイッチの偏波依存特性に大きく影響を受ける.本研究では,偏波依存損失(PDL : Polarization Dependent Loss)の小さい光スイッチとして知られるPLZT光スイッチを用いることにより,光パケットスイッチの偏波依存低減を目指しているが,実際にスイッチを多段に接続したシステム構成では,PDLが無視できないものであった.今回,導波路と電極構成を改善 …

    IEICE technical report 111(93), 13-18, 2011-06-16

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  • 2

    Linear Polarization Switchable Microstrip Array Antenna using SPOT Switch Circuit  [in Japanese]

    Ushijima Yu , Nishiyama Eisuke , Aikawa Masayoshi

    本研究においては,SPDTスイッチ回路を用いた直線偏波切り替え機能を有するマイクロストリップアレーアンテナの構成法を新たに提案する.このアンテナは,エアーブリッジを積極的に活用する直線偏波共用マイクロストリップアレーアンテナと高周波機能回路との一体複合した機能アレーアンテナである.ここでは,高周波機能回路として,両平面回路技術を用いたSPDTスイッチ回路を提案し,アンテナと一体複合させる.両平面回 …

    IEICE technical report. Antennas and propagation 111(29), 7-10, 2011-05-05

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  • 3

    Evolution of Linear Moduli and Remanent State Variables during Polarization Reversal in a Lead Zirconate Titanate Wafer at Various Temperatures

    Kim Yong Soo , Kim Sang-Joo

    … A poled lead zirconate titanate (PZT) wafer is subjected to electric field loading of pulse type whose magnitude is increasing until polarization direction is completely reversed. … During the complete cycle of polarization reversal, electric displacement in thickness direction and in-plane strain are measured in both loaded and unloaded states. … From the measured data, permittivity and piezoelectric coefficient are evaluated and fitted as linear functions of remanent polarization and temperature. …

    Jpn J Appl Phys 50(3), 031503-031503-6, 2011-03-25

    The Japan Society of Applied Physics

  • 4

    Ultrafast Polarization Switching in Ferroelectric Polymer Thin Films at Extremely High Electric Fields

    Ishii Hajime , Nakajima Takashi , Takahashi Yoshiyuki , Furukawa Takeo

    … Polarization switching dynamics at extremely high electric fields were measured for a 50-nm-thick ferroelectric vinylidene fluoride/trifluoroethylene copolymer film. … Using a fast-rise voltage pulse with minimal duration, we obtained a switching time of as fast as 2 ns at an electric field of 800 MV/m without electrical breakdown. … Distorted switching curves due to limited voltage rise time were shown to be reproducible by means of nonlinear superposition. …

    Applied Physics Express 4(3), 031501-031501-3, 2011-03-25

    The Japan Society of Applied Physics References (19)

  • 5

    Contamination Evaluation of High Duty Cycle, Space-Qualified Wheel Mechanisms for Onboard Telescopes  [in Japanese]

    IMADA Shinsuke , SHIMIZU Toshifumi , WATANABE Kyoko , BANDO Takamasa , TSUNETA Saku , HARA Hirohisa

    次期太陽観測衛星計画(SOLAR-C)用観測望遠鏡への搭載を目指して,国内開発中の高頻度回転駆動機構の要素検討を行っている.これまでミッションライフを通じて数100万-1000 万回以上動作させ得る可動機構は,日本国内で開発されておらず,「ひので」や「ようこう」では海外機器の一部として導入して実現させてきた.コンタミネーション管理レベルの厳しい望遠鏡内部で使用される長寿命(数100万-1000 万 …

    JAXA research and development report JAXA-RR-10-012, 1-13, 2011-03

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  • 6

    Polarization Manipulation via Orientation Control in Polycrystalline BiFeO3 Thin Films on Biaxially Textured, Flexible Metallic Tapes

    Shin Junsoo , Goyal Amit , Jesse Stephen , Heatherly Lee

    … The crystallographic orientation and polarization direction were confirmed using X-ray diffraction and piezoresponse force microscopy (PFM), respectively. … Switching spectroscopy PFM demonstrated that the switching polarization in (111)-oriented polycrystalline BiFeO3 films is higher than that in (101)- or (001)-oriented films. …

    Applied Physics Express 4(2), 021501-021501-3, 2011-02-25

    The Japan Society of Applied Physics References (15)

  • 7

    4x4 InAlGaAs/InAlAs Optical Switch Fabric by Cascading Mach-Zehnder Interferometer-type Optical Switches with Low-power and Low-polarization-dependent Operation  [in Japanese]

    UEDA Yuta , KOYAMA Noriaki , KAMBAYASHI Kazuki , FUJIMOTO Shinji , UTAKA Katsuyuki , SHIOTA Takashi , KITATANI Takeshi

    次世代の光ネットワークでは、光パケット信号の経路を光のまま切り替える高速な光スイッチが不可欠である。我々は、InAlGaAs/InAlAs半導体を用いた2x2マッハツェンダー干渉計型光スイッチを作製して、実験的に偏光無依存で-20dB以下の低クロストークと約3ナノ秒の高速スイッチング動作を3.5mAの低電流にて実現してきた。今回、ポート数拡張のために、5つの従来素子をカスケード接続する事によって4 …

    IEICE technical report 110(431), 77-80, 2011-02-21

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  • 8

    128 x 128 port 3D-MEMS optical switch module and its optical performance  [in Japanese]

    KAWAJIRI Yuko , NEMOTO Naru , MIZUKAMI Masato , YAMAGUCHI Joji , UCHIYAMA Shingo , SHIMOYAMA Nobuhiro , SAKATA Tomomi , SATO Yasuhiro

    ポート数128の3D-MEMS光スイッチコアモジュールを試作し,光パス接続特性を評価した.本コアモジュールの光学系は,光入出力ポートとして用いる一対のコリメータアレイの間に一対のMEMSミラーアレイを対向させて配置したZ型の構成を有する.開発した128ポートコリメータアレイのビーム出射角度誤差は<0.065°と極めて小さく,コリメートビームの出射角度誤差に起因するMEMSミラー上でのケラレ損 …

    Technical report of IEICE. LQE 110(396), 137-140, 2011-01-20

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  • 9

    128 x 128 port 3D-MEMS optical switch module and its optical performance  [in Japanese]

    KAWAJIRI Yuko , NEMOTO Naru , MIZUKAMI Masato , YAMAGUCHI Joji , UCHIYAMA Shingo , SHIMOYAMA Nobuhiro , SAKATA Tomomi , SATO Yasuhiro

    ポート数128の3D-MEMS光スイッチコアモジュールを試作し,光パス接続特性を評価した.本コアモジュールの光学系は,光入出力ポートとして用いる一対のコリメータアレイの間に一対のMEMSミラーアレイを対向させて配置したZ型の構成を有する.開発した128ポートコリメータアレイのビーム出射角度誤差は<0.065°と極めて小さく,コリメートビームの出射角度誤差に起因するMEMSミラー上でのケラレ損 …

    Technical report of IEICE. OPE 110(395), 137-140, 2011-01-20

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  • 10

    128 x 128 port 3D-MEMS optical switch module and its optical performance  [in Japanese]

    KAWAJIRI Yuko , NEMOTO Naru , MIZUKAMI Masato , YAMAGUCHI Joji , UCHIYAMA Shingo , SHIMOYAMA Nobuhiro , SAKATA Tomomi , SATO Yasuhiro

    ポート数128の3D-MEMS光スイッチコアモジュールを試作し,光パス接続特性を評価した.本コアモジュールの光学系は,光入出力ポートとして用いる一対のコリメータアレイの間に一対のMEMSミラーアレイを対向させて配置したZ型の構成を有する.開発した128ポートコリメータアレイのビーム出射角度誤差は<0.065°と極めて小さく,コリメートビームの出射角度誤差に起因するMEMSミラー上でのケラレ損 …

    IEICE technical report 110(394), 137-140, 2011-01-20

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  • 11

    Design of a multiband planar antenna for polarization switching with PIN diodes  [in Japanese]

    山浦 健太 , 木村 雄一 , 羽石 操

    IEICE technical report 111(128), 115-119, 2011-07-13

  • 12

    Effects of Electric Field and Poling on the Mode I Energy Release Rate for Two Symmetric Edge Cracks in Rectangular Piezoelectric Ceramic Strips

    SHINDO Yasuhide , NARITA Fumio , MATSUDA Takuya

    … A nonlinear plane strain finite element analysis was performed, and the effect of localized polarization switching on the energy release rate was discussed for the permeable, impermeable, open and discharging cracks under a high negative electric field. …

    Journal of Solid Mechanics and Materials Engineering 5(7), 335-347, 2011

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  • 13

    Unusual Formation of Switchable Hexagonal Columnar Phase by Bent-Shaped Molecules with Low Bent-Angle Naphthalene Central Core and Alkylthio Tail

    Li Xiaodong , Kang Sungmin , Lee Seng Kue , Tokita Masatoshi , Watanabe Junji

    … and exhibits polar switching with spontaneous polarization along the column axis. …

    Jpn J Appl Phys 49(12), 121701-121701-6, 2010-12-25

    The Japan Society of Applied Physics

  • 14

    Inverse Current-Induced Magnetization Switching in Magnetic Tunnel Junctions with Fe4N Free Layer

    Isogami Shinji , Tsunoda Masakiyo , Komasaki Yosuke , Sakuma Akimasa , Takahasi Migaku

    … Current-induced magnetization switching (CIMS) in CoFeB (pinned layer)/MgO/Fe4N (free layer) magnetic tunnel junctions (MTJs) was investigated at room temperature and an inverse CIMS phenomenon was clearly identified. … From the current-field magnetic phase diagram, determined from the dependence of the switching field on the bias current, the direction of spin-transfer torque was found to be opposite to that observed in CoFeB/MgO/CoFeB-MTJs. …

    Applied Physics Express 3(10), 103002-103002-3, 2010-10-25

    The Japan Society of Applied Physics References (19) Cited by (1)

  • 15

    High-quality Bismuth-based Ferroelectric Single Crystals Obtained by Defect Control  [in Japanese]

    Noguchi Yuji , Kitanaka Yuuki , Miyayama Masaru

    無機材料において,格子欠陥が悪影響を及ぼして,本来の物性を隠してしまうことがある.強誘電体では,少量の欠陥は分極の反転に必要不可欠であるが,欠陥の濃度が高くなると,様々な問題を引き起こす.Pb系材料の代替物質として期待されているBi系ペロブスカイト型強誘電体では,過去60年間にわたり,欠陥の問題が原因で,基礎物性の評価が可能な単結晶は得られていなかった.本稿では,著者らが世界に先駆けて開発した,高 …

    Butsuri 65(10), 769-776, 2010-10-05

    CiNii Fulltext PDF - Subscription  References (60)

  • 16

    Anisotropic Polarization Switching in Tungsten Bronze Ferroelectrics in Binary (Bi1/2Na1/2)Nb2O6–BaNb2O6 System

    Watanabe Takayuki , Hayashi Jumpei , Miura Kaoru

    … To evaluate the orientation of spontaneous polarization, (001)- and ($hk0$)-oriented fiber-textured ceramics were prepared for $x=0.2$, 0.25, and 0.3 by slip casting under a strong magnetic field. … Clear hysteresis loops of polarization–electric field were observed for (001)-oriented orthorhombic ceramics ($x=0.2$ and 0.25) at room temperature, while the polarization induced in the ($hk0$)-oriented or tetragonal ceramics ($x=0.3$) varied proportionally to the external electric field. …

    Jpn J Appl Phys 49(9), 09MD12-09MD12-4, 2010-09-25

    The Japan Society of Applied Physics

  • 17

    Polarization and Piezoelectric Properties of High Performance Bismuth Sodium Titanate Single Crystals Grown by High-Oxygen-Pressure Flux Method

    Suzuki Muneyasu , Morishita Akifumi , Kitanaka Yuuki , Noguchi Yuji , Miyayama Masaru

    … (Bi0.5Na0.5)TiO3 (BNT) single crystals were grown by flux method at a high oxygen pressure ($P_{\text{O$_{2}$}}$) of 1 MPa, and their polarization and piezoelectric properties were investigated. … BNT single crystals exhibited a saturated polarization hysteresis with remanent polarizations ($P_{\text{r}}$) of 31 μC/cm2 along [100]c, 44 μC/cm2 along [110]c and 54 μC/cm2 along [111]c. … These results show that spontaneous polarization of BNT is approximately 55 μC/cm2 or larger. …

    Jpn J Appl Phys 49(9), 09MD09-09MD09-5, 2010-09-25

    The Japan Society of Applied Physics

  • 18

    Switching Dynamics in Ferroelectric Vinylidene Fluoride–Trifluoroethylene Copolymer Thin Film with $\alpha$,$\omega$-Dihexylsexithiophene Semiconductor Layer

    Nakajima Takashi , Nakamura Marika , Furukawa Takeo , Okamura Soichiro

    … Ferroelectric switching dynamics in thin vinylidene fluoride–trifluoroethylene copolymer films with an organic semiconductor $\alpha$,$\omega$-dihexylsexithiophene layer have been investigated on the basis of the measurements of the electrical properties including $D$–$E$ hysteresis loop, switching characteristics, and capacitance changes. … The authors elucidate that the full polarization reversal can be accomplished and the depletion is maintained at zero bias field. …

    Jpn J Appl Phys 49(9), 09MC12-09MC12-5, 2010-09-25

    The Japan Society of Applied Physics

  • 19

    High-Performance Ferroelectric Bi4Ti3O12 Single Crystals Grown by Top-Seeded Solution Growth Method under High-Pressure Oxygen Atmosphere

    Kitanaka Yuuki , Noguchi Yuji , Miyayama Masaru

    … Crystals grown at 960 °C at a $P_{\text{O$_{2}$}}$ of 0.9 MPa exhibited well-saturated hysteresis with a remanent polarization of 48 μC/cm2 and a coercive field of 29 kV/cm. … The results of piezoresponse force microscopy indicate that polarization switching is accomplished throughout the crystals. …

    Jpn J Appl Phys 49(9), 09MC06-09MC06-4, 2010-09-25

    The Japan Society of Applied Physics

  • 20

    Crystal Structures and Electrical Properties of Epitaxial BiFeO3 Thin Films with (001), (110), and (111) Orientations

    Sone Keita , Naganuma Hiroshi , Miyazaki Takamichi , Nakajima Takashi , Okamura Soichiro

    … It was found that the (001) epitaxial BFO film had a thin tetragonal layer with spontaneous polarization fixed in the downward direction near the substrate. … The downward build-in field facilitated the switching of upward polarization and caused asymmetric relaxation. …

    Jpn J Appl Phys 49(9), 09MB03-09MB03-6, 2010-09-25

    The Japan Society of Applied Physics