担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/tdei.2023.3235656

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acsaom.3c00093

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1541/ieejfms.143.123

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担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/tdei.2022.3216842

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/tdei.2022.3168375

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：John Wiley and Sons Inc  

Pulsed electroacoustic (PEA) space charge measurement of low-density polyethylene using a spin-coated poly(vinylidene fluoride-trifluoroethylene) thin film is demonstrated. The space charge profile of a low-density polyethylene film with a thickness of 150 μm is measured by PEA method. Compared with conventional 9 and 30-μm piezoelectric films, the space charge profile obtained by the 3-μm spin-coated film shows better spatial resolution. Furthermore, acoustic attenuation of a PEA signal is also analytically studied using the Kelvin-Voigt model for viscoelastic materials.

DOI： 10.1002/ecj.12292

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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担当区分：責任著者   記述言語：日本語  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electrical Engineers of Japan  

This paper describes results on growth promotion of bean sprouts by dielectric barrier discharge (DBD) treatment in air. Before cultivation, the mung beans between glass plates are exposed to DBD plasma produced by ac square voltage for 20 min. It is possible to increase in the growth speed of the bean sprouts by the DBD with an adequate voltage height. However, excess thermal stimulation produced by the higher electrical stress to the seeds results in the reduction of the growth speed. Statistical significance of the effect of DBD on the growth promotion can be observed when the seeds between the glass plates are cooled by ventilation with a blower. These results imply that the DBD treatment without the thermal stress can be a useful method to reduce the cultivation period of the bean sprouts in agricultural industry.

DOI： 10.1541/ieejfms.139.410

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electrical Engineers of Japan  

Pulsed electroacoustic (PEA) space charge measurements using a spin-coated Poly(vinylidene fluoride-trifluoroethvlene) P (VDF-TrFE) thin film are demonstrated. The thickness of the P(VDF-TrFE) thin fihn is determmed by a reflection mterference method. The piezoelectric properties of the P (VDF-TrFE) film such as polarization hysteresis curve, residual polarization and coercive electric field are measured using a Sawyer-Tower circuit. The acoustic signals detected by 3-, 9-, and 30-jim piezoelectric films show strong tlnckness dependence, and the anti-resonance frequencies of the three films are evaluated by fast Fourier transform analysis. The space charge profiles on a 125-^im polyimide film surface are measured by PEA method. Hie space charge profile obtained by the 3-jim P (VDF-TrFE) film shows better spatial resolution compared with the results obtamed other films.

DOI： 10.1541/ieejeiss.139.1134

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Institute of Electrical Engineers of Japan  

This paper presents an experimental study on water treatment by electrospray and plasma discharge from a syringe needle. Our aim is to improve the activity of the plasma-chemical reactions in the fog produced by the electrospray. In this study, we propose a pulsed power technique to allow alternating expansions streamer corona discharges and fine water droplets with an alternating frequency of the order of 102 Hz. Under a dc voltage without any ripples, it is difficult to achieve the alternating expansions of the streamer corona and the water droplets. For the successful control of the alternating expansions, an impulse voltage consisting of function-like front and long exponential tail are repeatedly superimposed onto the dc voltage. The discharge light signals detected by a photomultiplier indicate that the streamer propagation is caused by the function component of the superimposed impulse. High-speed photographic observations of the water droplets show that the streamer discharge is followed by the water spray expansions produced by the long tail component of the superimposed impulse. The long tail component has a very important role to deform a large water droplet on the needle tip from the hemispherical shape into the Taylor-cone shape. We confirm that the alternating expansions of the discharge and the water droplets are not allowed when the superimposed impulse dose not contain the long tail. The frequency component of the long tail is roughly equal to the natural vibration frequency of the hemispherical droplet on the needle tip. We confirm that the stability of the water spray propagation strongly depends on the frequency components of the superimposed impulse.

DOI： 10.1541/ieejfms.139.205

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Japan Society of Applied Physics  

The repetitive current spikes caused by possible fast carrier transport through a low-density polyethylene (LDPE) sheet under high DC fields from 0.1 to 2.0 MV/cm are simultaneously measured with space charge distributions. Although a constant dc voltage is applied to the sheet between a semi-conduction (SC) electrode and an Al-evaporated electrode, large current spikes of the order of 10-8 A are repeatedly superimposed onto the dc conduction current of the order of 10-10 A. Results of the space charge measurements indicate that the charge injection from the SC anode and the subsequent deep penetration into the LDPE bulk can be observed when the current spikes are repeatedly detected. In addition, we find that a phenolic antioxidant added into the LDPE has an inhibition effect not only on the space charge penetration but also on the repetitive current spikes. This finding suggests that the antioxidant additive produces a deep trapping site for fast-moving carriers.

DOI： 10.7567/JJAP.57.03EG08

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2331/suisan.17-00036

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2331/suisan.16-00090

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MYU, SCIENTIFIC PUBLISHING DIVISION  

Generally, space charge formation in dielectrics subjected to DC voltage results in the enhancement of a conduction current called space-charge-limited current (SCLC). In this study, we find an interesting phenomenon that the conduction current for a low-density polyethylene (LDPE) sheet does not increase with increasing applied voltage even though a large number of space charges are accumulated in its bulk. Simultaneous measurements of the conduction current and space charge distribution are carried out for a 150-gm-thick additive-free LDPE between a semiconduction anode and an aluminum-evaporated cathode. Under a low applied field of below 0.6 MV/cm, the current is proportional to the square of the applied field because the maximum field strength in LDPE becomes higher than the mean applied field strength due to space charge formation in the LDPE bulk. Both the space charge distributions and the corresponding field distributions obtained by the simultaneous measurement roughly agree with the theoretical distributions based on the SCLC model. By increasing the applied field, however, the steady-state current saturates although a large number of positive space charges are accumulated in the LDPE bulk. We confirm that the steady-state current is restricted when a large number of frozen positive charges in front of the cathode are formed causing the strong field enhancement at a limited local thin area. These results imply that the carrier mobility at the local thin area was reduced by the excess field enhancement.

DOI： 10.18494/SAM.2017.1541

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本複合材料学会  

Resistance variation and Joule heating of carbon fiber reinforced plastic after applying a large electric current pulse are investigated. The current has a pulse width of several microseconds and the typical peak value is 2 kA. A double-digit decrease in resistance of a cross-ply laminate is observed after applying the kA current pulse. The decrease in resistance of the cross-ply laminate can be controlled by varying the charge voltage in the pulse generator circuit. In the case of DC current Joule heating, the direction of heat conduction at the surface is parallel to the fiber direction of the cross-ply laminate. However, the kA current pulse locally heats in the vicinity of the electrode and the thermal profile is different from the DC current.

DOI： 10.6089/jscm.42.228

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1541/ieejfms.136.704

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1541/ieejfms.136.717

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

An improved interference method is proposed to determine ordinary and extraordinary refractive index dispersions of nematic liquid crystals (LCs). In this method, an LC cell coated with a thin metal layer is used as a Fabry-Perot interferometer, which shows us a sharp transmission fringe. To ensure high reliability, the wavelength dispersion of the refractive index of the metal is taken into account in fitting calculation. In spite of measuring ordinary and extraordinary components, the LC cell, polarizers, and other equipment are not rotated during the experiment. The index evaluation from a single spectrum avoids errors depending on the measurement position owing to non-uniformities of molecular orientation and cell thickness because we can obtain the two indices at exactly the same position. This system can adapt to a wide frequency range and does not require any specific wavelength light source or laser. We demonstrate the determination of ordinary and extraordinary refractive index dispersions of a nematic liquid crystal in the visible and near-infrared regions. Furthermore, we quantitatively reproduce the measured spectrum by calculation using the measured refractive indices. Published by AIP Publishing.

DOI： 10.1063/1.4964936

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掲載種別：研究論文（学術雑誌）  

DOI： 10.1541/ieejfms.136.434

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

Metal nanoparticles have become increasingly important in fields such as electronics, photonics, and biotechnology. In particular, anisotropic gold nanoparticles, such as gold nanorods, exhibit unique properties owing to their anisotropy. Optical properties of isolated gold nanorods and dimers of gold nanorods have been investigated from both experimental and theoretical points of view. We have reported a method for three-dimensional assembly of anisotropic gold nanoparticles by two-phase transfer in which the morphologies of the assemblies can be controlled by the aspect ratio of nanorods. In this study, we numerically calculate extinction spectra to investigate the plasmonic properties of bundlelike assemblies by the finiteelement method. Their plasmonic properties depend on not only the three orthogonal directions but also the alignment of the nanorod assembly. (C) 2016 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.55.03DD04

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IOP PUBLISHING LTD  

Microwave and millimeter-wave devices including a liquid crystal (LC) are increasingly attractive for the use in adaptive and controllable devices. Various types of microwave phase shifters having an LC transmission line have been studied (e.g. microstripline, coplanar waveguide, and rectangular waveguide). In conventional microwave devices, the response time after removal of voltage is slow because the LC layer in the devices is usually thick. In this study, the time response of the LC permittivity is studied experimentally and theoretically. Experimentally measured response curves having two time constants for decay are examined by using Frank's continuum theory with and without the backflow effect.

DOI： 10.1088/1742-6596/704/1/012021

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

The viscosity properties of an electrolyte solution, which consists of 1-methyl-3-propylimidazolium iodide (MPI-I) as an electrolyte and ethylisopropylsulfone (EiPS) as a solvent, using the shear horizontal (SH) wave device are investigated. The viscosities with several concentrations of the electrolyte in solutions are measured. The viscosity increases with increasing concentration of the electrolyte. The viscosity also increases with increasing applied voltage and depends on not applied voltage but applied electric field. Furthermore, the analytical solutions of the physical properties of the SH wave propagation are derived.

DOI： 10.1109/TDEI.2015.005091

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI AG  

Polarization characteristics of defect mode peaks in a one-dimensional (1D) photonic crystal (PC) with a nematic liquid crystal (NLC) defect layer have been investigated. Two different polarized defect modes are observed in a stop band. One group of defect modes is polarized along the long molecular axis of the NLC, whereas another group is polarized along its short axis. Polarizations of the defect modes can be tuned by field-induced in-plane reorientation of the NLC in the defect layer. The polarization properties of the 1D PC with the NLC defect layer is also investigated by the finite difference time domain (FDTD) simulation.

DOI： 10.3390/cryst5030394

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

Non-quarter-wave stacked dielectric multilayers including azobenzene polymer liquid crystal layers are investigated in this study. The azobenzene polymer liquid crystal has a photoinduced reversible refractive index based on photoisomerization. By using the reversible refractive-index change, the reflectance of a stopband can be controlled. In this system, the azobenzene molecules change their conformation when they are irradiated with ultraviolet (UV) or visible light. In general, stacking many layers of different thicknesses can produce broadband or multicolor reflections for a dielectric multilayer. However, in a multilayer having thick azobenzene layers, UV or visible light used for controlling photoisomerization hardly reaches the bottom part of the multilayer because the light is mainly absorbed at its top surface. To solve this problem, the dependence on the thickness ratio of the multilayer is investigated and a non-quarter-wave stacked multilayer having RGB reflections is experimentally demonstrated using thin azobenzene layers. (C) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.091701

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掲載種別：研究論文（学術雑誌）  

DOI： 10.1541/ieejfms.135.473

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Dielectric multilayer including azobenzene polymer liquid crystal acts as a one-dimensional photonic crystal and has optical-switchable reflection bands. The reflection intensity can be controlled by irradiation of ultraviolet (UV) or visible light, in which the optical switch is based on cis-trans photoisomerization. An increase in the number of layers prevents photoresponse in the multilayer including azobenzen layers because UV or visible light for control cis-trans isomerization hardly reach the bottom of the multilayer due to exponential decay of light intensity. In this study, the multilayer consisting of thin azobenzene layers is investigated. According to numerical calculations, the non-quarter-wave structured multilayer has multiwavelength reflection band. Angular dependence of reflection color from multiwavelength stopband is also studied using the XYZ color space. The non-quarter-wave multilayer suppresses reflection color change compared with conventional quarter-wave multilayer.

DOI： 10.1080/15421406.2015.1027989

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記述言語：日本語   出版者・発行元：日本液晶学会  

Wavelength dispersions of refractive indices of nematic liquid crystals have been studied. We use an interference method which can determine refractive indices of liquid crystals by fitting the interference pattern of transmission spectrum between experimental and calculated results. In this study, we demonstrate simultaneous measurement of dispersion of ordinary and extraordinary refractive indices for a nematic liquid crystal using interference analysis.

DOI： 10.11538/ekitou.2015.0__PA51

CiNii Books

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記述言語：日本語   出版者・発行元：日本液晶学会  

With characteristics of high specific surface area and nano size effects, nanofiber obtained from electrospinning method has attracted considerable interests in many fields such as medical and energy. With small pore size, we expected that nanofibers have interaction with nematic liquid crystal molecules. In our research, nanofiber/liquid crystal (LC) composites are prepared by inserting aligned nanofiber into thick LC layer. We confirm that composite devices have faster response time than that of pure LC device and the response time of composite devices is proportional to the concentration of fiber.

DOI： 10.11538/ekitou.2015.0__PB68

CiNii Books

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記述言語：日本語   出版者・発行元：日本液晶学会  

Chiral liquid crystals, such as cholesteric liquid crystal or ferroelectric liquid crystal are expected to be a candidate of a tunable photonic crystal. These liquid crystals have a property of selective reflection. Ferroelectric liquid crystals have a full pitch band that does not exist in cholesteric liquid crystals. The bandwidth of the full pitch band becomes wider at highly oblique incidence. In this study, we calculate deformations in a helical structure of a ferroelectric liquid crystal by applying voltage using continuum theory. Furthermore, we also calculate transmission spectra of the full pitch band of the ferroelectric liquid crystal with the helix deformation at oblique incidence.

DOI： 10.11538/ekitou.2015.0__PB51

CiNii Books

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記述言語：日本語   出版者・発行元：日本液晶学会  

Many researchers have been studied cholesteric liquid crystals as a one-dimensional photonic crystal. However, there are not so many studies of ferroelectric liquid crystals as a photonic crystal owing to low refractive index contrast. In this study, we focus on the full pitch band of a ferroelectric liquid crystal whose bandwidth becomes wider at highly oblique incidence. By varying an angle of incidence and an electric field, we independently control the peak wavelength and the bandwidth of the full pitch band of a ferroelectric liquid crystal.

DOI： 10.11538/ekitou.2015.0__PB50

CiNii Books

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

Nanofibers with diameters less than 1000nm assembled by electrospinning and with a large surface area per unit mass have been attracting considerable attention and are expected to affect the orientation of liquid crystals (LCs). Firstly, to determine the orientated nanofibers on an indium-tin-oxide (ITO) glass surface, the spectral analysis technique of using fast Fourier transform is applied. Optical observation is performed to confirm the orientation of LC molecules in a twisted nematic LC cell. Finally, optical measurement of an LC cell is carried out to estimate the threshold voltage of the LC in two types of twisted nematic LC cell: one with rubbed polyimide and the other with orientated nanofibers as the alignment layer. A twisted nematic LC is oriented in the cell using orientated nanofibers as the alignment layer and the threshold voltage of this cell agrees with that of the conventional polyimide rubbed cell. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.01AE03

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

This paper presents an experimental study on germination control for naked barley seed by using a repetitive pulsed power technique. Two kinds of tests, localized pulse electric field (PEF) treatment and dielectric barrier discharge (DBD) treatment, are carried out. In the first test, very short mono-polar pulses below 500 ns in width and below 5 kV in heights are applied to the seeds between point-plane electrodes with 500 pps repetition rate for 20 min. A fine stainless needle electrode is inserted into embryo region or endosperm region of the seed to clarify which region should be stressed by the localized PEF for the germination control. The germination rate of the seed after the PEF treatment is compared not only with that of the seed without any treatment (control) but also the seed with sham treatment, which means that the needle tip is inserted without voltage application. Results indicate that there is no effect of the PEF application into the endosperm region of the seed on the germination inhibition. On the other hand, the PEF application into the embryo region has an effect on the germination inhibition if the pulse width is long. In the second test, embryo region of the seed is exposed by the dielectric barrier discharges produced by the polarity-reversed voltage pulses with 100 ns in width. Evans Blue dyeing for the seeds is carried out to clarify the biological activity of the embryo cells. Embryo cell necrosis is caused by the 10 min discharge treatment. On the other hand, necrosis of the seed surface is not observed for the seed after the PEF treatment.

DOI： 10.1109/ISEIM.2014.6870780

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記述言語：日本語   出版者・発行元：日本液晶学会  

<p>Wavelength dispersions of refractive indices of azobenzene-polymer liquid crystal have been studied. To design an optical device using the azobenzene-polymer liquid crystal, the wavelength dispersions of the refractive are necessary. We here measur e the refractive index anisotropy for the azobenzene-polymer liquid crystal using interference analysis.</p>

DOI： 10.11538/ekitou.2014.0_PB52

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記述言語：日本語   出版者・発行元：日本液晶学会  

<p>The chiral smectic C phase of ferroelectric liquid crystals (FLCs) has a self-assembling helical structure which is regarded as a one-dimensional pseudo-photonic crystal. It is well known that a stopband of a FLC can be tuned in wavelength domain by changing tempera ture or electric field. We have studied the fullpitch band of an FLC stopband with independently tunable wavelength and bandwidth. In the previous report, the helix of the FLC was tuned by temperature. We here study the bandwidth control for the fullpitch band using electric field.</p>

DOI： 10.11538/ekitou.2014.0_PB39

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

The viscosity properties of an electrolyte solution, which consists of 1-methyl-3-propylimidazolium iodide (MPI-I) as an electrolyte and ethylisopropylsulfone (EiPS) as a solvent, using the shear horizontal (SH) wave device are investigated. The viscosities with several concentrations of the electrolyte in solutions are measured and the viscosity increases with increasing concentration of the electrolyte. The viscosity increases with increasing applied voltage and depends on not applied voltage but allied electric field. Moreover, the relation between viscosity and electrolyte concentration is clarified.

DOI： 10.1109/ICDL.2014.6893126

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記述言語：日本語   出版者・発行元：日本液晶学会  

<p>Nanofiber has characteristics such as high specific surface area and nano size effects. Nanofiber / liquid crystal (LC) composites were prepared by implanting aligned nanofiber obtained from electrospinning method into LC cell. In the composites, we confirmed that LC molecules oriented along the direction of nanofibers. We also confirmed that thicker nanofiber layer in the composite results in faster response time on the removal of control voltage of the LC.</p>

DOI： 10.11538/ekitou.2014.0_2C01

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

Water tree degradation is major problem for power transmission cables. Water treeing is typical of the processes involved in the aging of XLPE cables, and it is known that it causes degradation of insulation performance. To avoid catastrophic failure, a method for localization of this water-treed section is required. We here propose a water-tree detection using polarity-reversed voltage pulses propagation. The polarity-reversed voltage pulses are impulse-like voltages having a exponential tail. We obtained a water tree degradation cable by accelerated deterioration aging test and measured the voltage pulse propagation. The measured pulse waveform involves a signal reflected by non-50 Omega. Although the reflection signal is a small peak, the experimental results qualitatively agreed with calculation results.

DOI： 10.1109/ISEIM.2014.6870818

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

Metal nanoparticles have become more and more important to electronics, photonics, biotechnology, and so on. In particular, anisotropic gold nanoparticles such as gold nanorods exhibit unique properties due to its anisotropy. We reported a method for three-dimensional assembling of anisotropic gold nanoparticles as well as gold nanospheres, by two-phase transfer. In this study, we numerically calculate extinction spectra to analyze the interparticle interaction for the assembled nanoparticles.

DOI： 10.1109/ISEIM.2014.6870762

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The optical properties of stopbands of a ferroelectric liquid crystal (FLC) in a chiral smectic C phase are investigated experimentally and theoretically. Chiral smectic and cholesteric liquid crystals are regarded as pseudo photonic crystals. They exhibit Bragg reflections corresponding to half- and full-pitch bands. The characteristics of the Bragg reflections at oblique incidence are discussed on the basis of numerical calculations. The full-pitch band of an FLC becomes deeper and wider at highly oblique incidence. Using this characteristic, we demonstrated an FLC stopband with independently tunable wavelength and bandwidth by controlling the temperature and incident angle, respectively. © 2014 The Japan Society of Applied Physics.

DOI： 10.7567/JJAP.53.01AE01

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

This paper presents an experimental study on toluene gas decomposition using repetitive surface discharges on a dielectric barrier subjected to very fast polarity-reversed pulse voltage or standard ac (sinusoidal or square) voltages. 300 ppm of toluene with dry air or with humid air is injected into a plasma reactor with a double cylindrical glass tubes. Effect of the very fast polarity reversal on toluene decomposition in humid air is studied. The surface discharge inception voltage for the polarity-reversed pulse is lower than that for both sinusoidal and square ac. Intense surface discharge light spread on the glass barrier when the voltage polarity is rapidly changed from negative to positive. Therefore, the toluene decomposition ratio for the polarity-reversed pulse is higher than those for the standard ac voltages. Under a dry air condition, no remarkable differences of the energy efficiency for toluene decomposition are observed between the applied voltages. However, the energy efficiency for the sinusoidal ac becomes lower than those for the other voltages under a humid air condition. The energy loss due to Joule heating is produced by the conduction current along the wet surface during the voltage polarity is changing. Therefore, the energy efficiency under the humid condition depends on the rise time of the polarity reversal of the applied voltage.

DOI： 10.1109/ISEIM.2014.6870815

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

In this paper, we propose an improved calculation method for analyzing the three-dimensional motion of nematic liquid crystal molecules in studies of all types of microwave transmission line loaded with a nematic liquid crystal. This method is applied to the analysis of motion of nematic liquid crystal molecules under a nonuniformly distributed electric field generated by asymmetric electrodes in a microstripline structure as a comprehensive example. Then, the dielectric constant distribution of the nematic liquid crystal layer, the effective dielectric constant in a microwave electric field, and the phase shift of a microwave in the microstripline loaded with a nematic liquid crystal are calculated. The rise time, decay time, and phase shift of a microwave phase shifter using a microstripline loaded with a nematic liquid crystal are also calculated. The differences in these response characteristics and their dependences on the width of the center conductor of the microstripline are determined by calculation and confirmed by performing experiments on the microwave phase shifters and an optical experiment on the retardation of the microstripline loaded with a nematic liquid crystal structure. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.121701

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：School of Electrical Engineering and Informatics  

This paper presents an experimental study on long time range breakdown of Low Density Polyethylene (LDPE) under very high dc applied fields (Emean) of 2.0 MV/cm or 3.0 MV/cm. Breakdown time lag and space charge distribution are simultaneously measured for a 200-μm-thick LDPE sheet with positive-semicon and negative-evaporated Al electrodes. A voltage is applied to the sheet until the dc breakdown occurs. 20 samples are tested for both the applied voltages. It should be remarked that 50% survivor probability T50, corresponding to time in which breakdown occurs for 10 samples out of 20, is 70 min for 40 kV, whereas it is 90 min for 60 kV. Results of the space charge measurement by pulsed electro acoustic (PEA) method indicates that a large number of positive charges are injected from the semicon-anode and they are accumulated in the bulk of LDPE, so that field distribution in LDPE is strongly distorted. The maximum field strength Emax(t) in LDPE after the space charge penetration for 60 kV becomes higher than that for 40 kV. However, the distortion ratio Emax(t)/Emean under 40 kV is higher than that under 60 kV. This is because the positive charges packet produced by 40 kV penetrates into deeper area of the bulk as compared with that by 60 kV.

DOI： 10.15676/ijeei.2013.5.2.1

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記述言語：日本語   出版者・発行元：日本液晶学会  

Orientated nanofibers of PVA are produced by using electrospinning method. In this technique, the improved drum collector is used because the electric field concentration compared with normal drum. The thickness of nanofibers ranges from several micrometers to several tens micrometers. Nanofibers / nematic liquid crystal cell is fabricated and dielectric and optical properties are measured, compared with normal rubbing cell. We founded that rise time and threshold voltage of nanofiber cell are equal to normal polyimide cell. However, decay time of nanofiber cells is shorter than of polyimide cell.

DOI： 10.11538/ekitou.2013.0__PB55

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記述言語：日本語   出版者・発行元：日本液晶学会  

An RGB reflecting multilayer including azobenzene-polymer liquid crystal has been studied. The azobenzene-polymer liquid crystal has a photoinduced reversible refractive index based on photoisomerization. By using the reversible refractive-index change, the reflectance of the multilayer including azobenzene-polymer can be controlled. In this system, the azobenzene molecules change their conformation as a result of a cis-trans transition when they are irradiated with ultraviolet (UV) light. Unfortunately, in a thick multilayer, UV light does not reach the bottom part of the multilayer because UV light is mainly absorbed at its top surface. To solve this problem, the thickness ratio of the multilayer has been studied. We found that an RGB reflection appears by stacking thin azebenzene layers and thick other layers. This is because that the asymmetric periodic structure consists of many frequency components.

DOI： 10.11538/ekitou.2013.0__2a04

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：School of Electrical Engineering and Informatics  

This paper presents an experimental study on repetitive partial discharge inception probability of twisted enameled wires subjected to modified inverter-surges. In order to obtain the probability curves as a function of the voltage amplitude, we develop an automatic measurement system of partial discharge inception probability for the twisted enameled wires subjected to the repetitive pulses with step-by-step increasing in the voltage height. Very fast oscillated pulses with or without polarity-reversal and an impulse-like pulse without oscillation are used as the modified inverter-surges. In the test for the impulse-like voltage, repetitive partial discharge inception voltage (RPDIV) decreases with increasing the pulse width. On the other hand, RPDIV for the polarity-reversed pulse with a higher oscillation cycle is lower than that for the pulse with lower oscillation cycle. The difference of PD inception probability between the voltage waveforms will be discussed on the basis of charge dynamics on the wire surfaces.

DOI： 10.15676/ijeei.2013.5.1.5

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：School of Electrical Engineering and Informatics  

We observe streak images of dc pre-breakdown in silicone-oil (10 cSt, 100 cSt and 10000 cSt)/low density polyethylene (30 μm in thickness) composite insulation under needle/sphere electrode by using the 20 meter long image guide scope and a streak camera. In the case of composite insulation with 10 cSt of silicone-oil, breakdown light propagates from the needle side under both voltage polarity. However, in the 10000 cSt case, breakdown light propagates from the film side under the negative voltage polarity. The mechanism of these transient phenomena are discussed in this paper.

DOI： 10.15676/ijeei.2013.5.1.9

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：OPTICAL SOC AMER  

The chiral smectic C phase of ferroelectric liquid crystals (FLCs) has a self-assembling helical structure which is regarded as a one-dimensional pseudo-photonic crystal. It is well known that a stopband of a FLC can be tuned in wavelength domain by changing temperature or electric field. We here have demonstrated an FLC stopband with independently tunable wavelength and bandwidth by controlling temperature and incident angle. At highly oblique incidence, the stopband does not have polarization dependence. Furthermore, the bandwidth at highly oblique incidence is much wider than that at normal incidence. The mechanism of the tunable stopband is clarified by considering the reflection at oblique incidence. (C) 2012 Optical Society of America

DOI： 10.1364/OE.20.006191

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記述言語：日本語   出版者・発行元：日本液晶学会  

The chiral smectic C phase of ferroelectric liquid crystals (FLCs) has a self-assembling helical structure which is regarded as a one-dimensional pseudo-photonic crystal. It is well known that a stopband of a FLC can be tuned in wavelength domain by changing temperature or electric field. We here have demonstrated an FLC stopband with independently tunable wavelength and bandwidth by controlling temperature and incident angle. At highly oblique incidence, the stopband does not have polarization dependence. Furthermore, the bandwidth at highly oblique incidence is much wider than that at normal incidence. The mechanism of the tunable stopband is clarified by considering the reflection at oblique incidence.

DOI： 10.11538/ekitou.2012.0__3c09

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN SOC APPLIED PHYSICS  

We investigate cholesteric liquid crystal (CLC) orientation in a hollow fiber by microscopic observation and reflection spectrum measurement. The existence of a helical structure in the fiber is confirmed by comparing the reflection spectra of the CLC in the fiber with those of the CLC in a sandwich cell. The results of reflection measurement and microscopic observation indicate that the CLC helix is oriented concentrically in the fiber. Finite-difference time-domain (FDTD) simulation results also support the experimental results. The concentrically oriented CLC can be regarded as a quasi-two-dimensional photonic crystal despite its one-dimensional CLC helix. Two-dimensional laser emission is achieved by optically pumping the fiber infiltrated with a dye-doped CLC. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.111601

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

Viscosity properties of liquids, liquid crystals, electrolyte solutions and ionic liquids using the shear horizaontal wave are investigated. The measured viscosities of glycerol/water solutions well agree with the reference values. Using orientation treatment and application of voltage, the electroviscosity effect of liquid crystal is confirmed by this method. Moreover, the relation between viscosity and ionic conductivity of ionic liquids, which followed Walden's rule is obtained.

DOI： 10.1109/ICDL.2011.6015492

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

A novel phase shifter loaded with LC for operation in the microwave band has been proposed and its application to array antenna is demonstrated experimentally. The phase shifting operation is based on the anisotropy of dielectric permittivity of the liquid crystal caused by the change of applied electric field. As an application of such LC loaded phase shifter, we utilized the phase shifter as a means for electrically controlling the phase of microwave signal fed to a two-element array antenna comprised of two microstrip antennas that was designed for operating at 20-GHz-band. We have confirmed that the radiation directivity of the array antenna can be controlled by the applied bias voltage.

DOI： 10.1080/15421406.2011.570555

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

Viscosity properties of liquids, liquid crystals, electrolyte solutions and ionic liquids using the shear horizaontal wave are investigated. The measured viscosities of glycerol/water solutions well agree with the reference values. Using orientation treatment and application of voltage, the electroviscosity effect of liquid crystal is confirmed by this method. Moreover, the relation between viscosity and ionic conductivity of ionic liquids, which followed Walden's rule is obtained.

DOI： 10.1109/ICDL.2008.4622458

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Light propagation into a photonic crystal infiltrated with a nematic liquid crystal is numerically investigated. At a high-order photonic band, photonic crystals generally exhibit interesting characteristics such as a negative refraction and a superprism effect. Our numerical results show that the sign of an effective refractive index of the tunable photonic crystal can be controlled at a certain frequency by changing molecular orientation. Furthermore, using a combination of positive and negative index photonic crystals, a light could be redirected 90 degrees without a waveguide structure.

DOI： 10.1080/15421406.2011.571976

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

A coplanar waveguide type microwave phase shifter using ferroelectric liquid crystal is constructed and its fundamental characteristics are measured. An analysis procedure of the effective permittivity of the phase shifter is explained. The decrease of the width of the center conductor in the phase shifter leads the increase of the dielectric permittivity change, consequently increasing the phase shift. The distance between the center conductor and ground plane needs the same as the width of the center conductor. Furthermore, it is confirmed that the arrangement of the dielectric substrate instead of the liquid crystal layer is useful technique.

DOI： 10.1080/15421406.2011.570550

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

We investigate the effective viscosity of a nematic-liquid-crystal (NLC) for viscosity measurement using a shear horizontal (SH) wave propagating through a glass substrate loaded with the NLC. The phase measurement of the SH wave determines the NLC viscosity because SH wave propagation depends on loaded material viscosity. Using this viscosity measurement, we can also determine the viscosity anisotropy of the NLC with director reorientation. In experiment, phase shifts are detected when voltages are applied to a NLC layer. The measured phases show an unpredictable shift which cannot be explained by conventional director angular dependence of viscosity. To analyze the phase shifts quantitatively, we introduce average effective viscosity for the viscosity measurement using SH wave. This effective viscosity is calculated considering the NLC director configuration and SH wave penetration into the NLC layer. The phase shifts calculated from the effective viscosity well agree with the measured phase shifts. The use of effective viscosity enables quantitative analysis for NLC viscosity measurement using the SH wave and also clarifies the mechanism of the unpredictable SH wave phase shift with director reorientation. © 2010 The American Physical Society.

DOI： 10.1103/PhysRevE.81.061703

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSICAL SOC  

We investigate the effective viscosity of a nematic-liquid-crystal (NLC) for viscosity measurement using a shear horizontal (SH) wave propagating through a glass substrate loaded with the NLC. The phase measurement of the SH wave determines the NLC viscosity because SH wave propagation depends on loaded material viscosity. Using this viscosity measurement, we can also determine the viscosity anisotropy of the NLC with director reorientation. In experiment, phase shifts are detected when voltages are applied to a NLC layer. The measured phases show an unpredictable shift which cannot be explained by conventional director angular dependence of viscosity. To analyze the phase shifts quantitatively, we introduce average effective viscosity for the viscosity measurement using SH wave. This effective viscosity is calculated considering the NLC director configuration and SH wave penetration into the NLC layer. The phase shifts calculated from the effective viscosity well agree with the measured phase shifts. The use of effective viscosity enables quantitative analysis for NLC viscosity measurement using the SH wave and also clarifies the mechanism of the unpredictable SH wave phase shift with director reorientation.

DOI： 10.1103/PhysRevE.81.061703

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

The authors report continue tuning of the lasing wavelength in cholesteric liquid crystals (ChLCs) by an applied electrical fields. Although the pitch length and the corresponding lasing wavelength is sensible to external fields, only a discrete shift in the pitch is observed in the conventional cell configuration where the helix axis is lying the cell-normal direction, since the molecules are anchored to a single direction at the substrate interfaces. In this study, continuous wavelength tuning is achieved by laying the helix in the cell-plane direction, mitigating the effects of anchoring: this alignment is attained simply by applying an electric field while cooling the sample from the isotropic state, in a planarly rubbed sandwich cell. We also show that the tuning characteristics as that predicted based on calculations using the elastic theory.

DOI： 10.1080/15421400903408756

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN SOC APPLIED PHYSICS  

The photonic band structure and circular-polarization dependence of the transmission properties of cholesteric blue phase II were analyzed using a finite-difference time-domain method based on a double-twist cylinder model. The polarization dependence of the calculated band structure was not recognized in the same manner as that in previous studies. However, it can be clearly observed that the calculated transmission spectra depend on the circular polarization; this result agrees well with experimental results. On the basis of the circular-polarization dependence of the transmission spectra in the case of a thick sample, it can be indicated that a total reflection band appears in the selective reflection band. (C) 2010 The Japan Society of Applied Physics

DOI： 10.1143/APEX.3.032001

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人電子情報通信学会  

コプレーナ線路に浮遊電極を配した伝送線路(CPW-FE)に液晶を装荷したマイクロ波帯液晶装荷移相器の誘電率変化すなわち誘電異方性(Δε)と可変位相量及び応答時間の理論計算を行い,実験値との照合を行った.CPW-FE中の液晶配向の空間分布は,液晶の連続体理論に基づき計算しており,液晶配向分布とCPWの基本モードの高周波電界を用いて液晶装荷CPW-FE移相器の実効誘電率及び応答時間を求めている.また,液晶駆動用電圧の印加方向の変化に伴う可変位相量,誘電異方性及び応答時間の実験値と計算値の比較では,印加電圧に対する依存性は定性的によい一致を得ている.更に液晶配向分布とCPWの高周波電界分布を用いて,液晶装荷CPW-FE移相器の中心導体幅等の構造の違いが誘電率変化及び応答時間に及ぼす影響等を考察している.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

The effective permittivity and the variable phase shift of a microwave phase shifter using a liquid crystal loaded coplanar waveguide with floating electrode (CPW-FE), and the dielectric birefringence (epsilon) of the liquid crystal layer in a liquid crystal microwave phase shifter are calculated, taking into account molecular orientations in a liquid crystal layer. The effective permittivity and the dielectric birefringence are determined from the liquid crystal molecular orientations and CPW-FE high-frequency electric field. Using liquid crystal continuum theory, we obtain a liquid crystal molecular orientation controlled by a bias voltage. Calculations of the dependence of the variable phase shift on the bias voltage and the dielectric birefringence qualitatively agree with measurements. Furthermore, the calculations confirm the mechanism of the change in permittivity.

DOI： 10.1080/15421400903112085

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Rapid thermal annealing enables removal of orientation defects in planar cholesteric liquid crystal (CLC). We investigate influence of rapid annealing and cooling on molecular orientation in CLC. Annealing temperature strongly affects the number of treatment cycles required for improved orientation, and an effective annealing temperature range is very narrow. Both annealing and cooling are effective for removal of orientation defect in planar CLC. The number of the treatment cycles depends on viscosity of CLC. The rapid thermal processing is applicable to chiral dopants having various thermal properties.

DOI： 10.1080/15421400903058718

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

We study optical properties of nanoimprinted gratings infiltrated with liquid crystal (LC). One-dimensional grating of a line-spacing pattern is used as a distributed feedback cavity. After filling LC into the trenches of the grating, the LC molecules align along the trench of grating and it shows uniform planar alignment. By optical pumping, laser emission occurs and the laser wavelength can be tuned by temperature control or application of voltage. We also demonstrate control of diffraction intensities from a two-dimensional grating using LC molecular reorientation in micro space.

DOI： 10.1080/15421400903051424

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

We demonstrate the improvement of the orientation of a planar cholesteric liquid crystal (CLC) by rapid thermal processing. Rapid thermal annealing and cooling reduce the number of orientation defects in the planar CLC. The annealing temperature strongly affects the number of treatment cycles required for improved orientation and the effective annealing temperature range is very narrow. In a treated cell, scattering is reduced and sharp band edges appear in the transmission spectrum. The proposed method is applicable to chiral dopants having various thermal properties. Through this method, a uniform planar CLC cell with a thickness greater than 100 mu m is achieved. (c) 2008 American Institute of Physics.

DOI： 10.1063/1.2913686

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記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Wiley-VCH Verlag GmbH &amp; Co. KGaA  

DOI： 10.1002/9783527621880.ch14

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

A microwave variable phase shifter of a coplanar waveguide with floating electrodes using a ferroelectric liquid crystal is discussed. The electric field of the microwave is calculated in the phase shifter and the electric wave propagation of the coplanar waveguide mode is confirmed. The measured phase shift is proportional to the microwave frequency and the anisotropy of the refractive index in the microwave region is estimated to be 45% of that in the visible region. The measured phase shift increases with increasing applied voltage from an offset voltage. The response time is less than 1.6 ms, and a highspeed microwave variable phase shifter is realized.

DOI： 10.1143/JJAP.47.1367

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN SOC APPLIED PHYSICS  

We have demonstrated lasing in cholesteric liquid crystals (CLCs) of various thicknesses oriented by acoustic streaming. Although alignment control of CLC molecules in a thick cell is difficult, acoustic streaming can change the CLC alignment from a focal conic state to a planar state by molecular flow. The molecular reorientation leads to making a large uniform CLC layer that can function as a laser cavity. Therefore, laser action cannot be observed in the untreated thick cells because of the focal conic state, while a sharp emission appears from the thick cells treated by acoustic streaming. Furthermore, lasing wavelength shifts with a small wavelength interval are realized using a large cavity.

DOI： 10.1143/JJAP.47.1363

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掲載種別：研究論文（学術雑誌）  

Electrical tuning of laser wavelength is demonstrated using a liquid-crystal/polymer grating fabricated by nanoimprint lithography. Laser emission occurs at a wavelength near 700 nm, which corresponds to the first order of a 200 nm period grating. With increasing applied voltage, the lasing spectrum begins to shift to shorter wavelengths at 10V, and then a 10nm shift is achieved with an applied voltage of 30V. This is due to the refractive index change of the liquid crystal in the trench of the polymer grating by field-induced molecular reorientation. © 2008 The Japan Society of Applied Physics.

DOI： 10.1143/APEX.1.012003

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

The acoustic phase change of a shear horizontal (SH) wave propagating into a nematic liquid crystal cell structure is measured under application of electric field. The numerical analyses are also performed by considering director distribution and viscosity distribution in the nematic liquid layer. The effective viscosity was calculated from the viscosity distribution profiles and the particle velocity of the SH wave in the liquid crystal layer. The liquid crystal viscosity calculated from the measured acoustic phase change under application of electric field is excellent agreement with the calculated effective viscosity.

DOI： 10.1109/ICDL.2008.4622457

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-V C H VERLAG GMBH  

Liquid crystals including chiral molecule have a self-organized helical structure with nano-scaled periodicity, which can be regarded as a one-dimensional (1D) photonic crystal. We have so far investigated lasing characteristics at an edge of the 1D photonic band gap (PBG) of dye-doped chiral liquid crystals such as cholesteric liquid crystal (CLC) and ferroelectric liquid crystal (FLC). A band-edge excitation effect on the CLC lasing has been experimentally demonstrated by matching the excitation laser wavelength to the higher energy-edge of the PBG of a dye-doped CLC. The wavelength tuning of the laser action upon changing electric field strength has been achieved in FLC. We have proposed the defect modes characteristic to the helicoidal structure of the chiral liquid crystal and demonstrated the lasing from the chiral defect modes. A twist defect mode in a transmission spectrum of the composite film consisting of two photopolymerized CLC layers has been experimentally demonstrated. A new type of defect mode in a chiral liquid crystal on the basis of the local deformation of the 1D periodic helical structure has also been proposed, and the possibility of the wavelength tuning has been demonstrated in this system. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

DOI： 10.1002/pssa.200776422

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN SOC APPLIED PHYSICS  

Mechanical vibration distributions of freely suspended ferroelectric liquid crystal films with various thicknesses in the range from 15 nm to 12 mu m induced by applying a sinusoidal electric field are observed using a laser Doppler vibrometer. Mechanical resonance profiles of the freely suspended film are represented in the form of mechanical vibration distributions. Resonance frequency increases with the number of mechanical resonance modes. Surface tension is calculated from the number of mechanical resonance mode, and the resonance frequency. The surface tension is not constant and is proportional to the thickness of the freely suspended film below 1.2 mu m.

DOI： 10.1143/JJAP.46.7128

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本液晶学会事務局  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

The dynamic responses of an acoustic phase to liquid crystal (LC) molecular reorientation in a shear horizontal (SH) wave device with an LC cell are measured by applying a voltage. The optical responses are also observed in order to determine the molecular director distributions in the device. The response of acoustic phase by removing the applied voltage is three orders of magnitude faster than the optical response. To investigate the effective viscosity acting on the SH wave propagation, the dynamic changes in the director distribution are calculated. Using the calculated director distribution, we obtain the effective viscosity acting on the SH wave propagation, which coincides qualitatively with the measured acoustic phase change.

DOI： 10.1143/JJAP.46.4734

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

We have demonstrated the reorientation of cholesteric liquid crystal (CLC) molecules in a thick cell by acoustic streaming. In the thick cell, the initial CLC does not have a planar alignment but a focal conic state in spite of the surface being coated with a planar polyimide and rubbed unidirectionally. The acoustic streaming effect changes the CLC alignment from a focal conic state to a planar alignment. The alignment of the treated cell including its defects is improved by storing the cell at room temperature for several days. Although the focal conic cell shows a low transmittance and a broad stop band due to light scattering. the treated cell reduces scattering and has the sharp band edges in the stop band.

DOI： 10.1143/JJAP.46.L489

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

The microwave variable phase shifter of a coplanar waveguide using ferroelectric liquid crystal with float electrodes, which are used for applying a dc voltage to a liquid crystal layer, is discussed. We confirmed the performance of the phase shifter in the frequency range from 10 to 30GHz and found that phase shift is proportional to the frequency of the microwave according to the theory. The measured phase shift increases with an increase in applied voltage. The response time of this phase shifter was less than 1 ms above 120 V and a very high speed variable phase shifter was achieved.

DOI： 10.1143/JJAP.46.L519

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

A low threshold and high efficiency laser based on dye-doped cholesteric liquid crystals (CLCs) is demonstrated using an input excitation with the same handedness of circular polarization as the helical structure of the sample at the shorter wavelength band edge of the reflection band. The responsible mechanism originates from the dramatic increase of the optical density of state (DOS) at the band edges. The calculated DOS of the CLC system confirms the authors' experimental results.(c) 2007 American Institute of Physics.

DOI： 10.1063/1.2710777

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

We have achieved single-mode laser action in a one-dimensional hybrid photonic crystal (HPC) containing cholesteric liquid crystal (CLC) as a defect and experimentally investigated the polarization characteristics of the laser light. The laser light emitted from the HPC containing the CLC was linearly polarized, which was different from that of the simple CLC, despite the CLC being contained in this structure. We have theoretically calculated the optical propagation to justify the experimental result. The calculated result was in good agreement with the experimental result and showed the difference in optical characteristics between the simple CLC and the HPC containing the CLC. (c) 2007 American Institute of Physics.

DOI： 10.1063/1.2434835

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

We analyze the dynamic response and optical properties of a high-speed defect mode switching that is based on a tunable defect mode in a one-dimensional photonic crystal with a nematic liquid crystal defect layer. The electro-optic responses of the defect mode switching are calculated considering the director distributions in the defect layer, which are determined using continuum theory. The calculated defect mode switching exhibits a response on the order of microseconds in spite of the use of the reorientation of nematic liquid crystal molecules. From the calculation, it is found that the fast response is realized using a narrow peak shift and a fast part of the molecular reorientation. Furthermore, the dependences of the switching response are clarified on several physical parameters. (c) 2007 American Institute of Physics.

DOI： 10.1063/1.2432877

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掲載種別：研究論文（学術雑誌）  

The acoustic phase of a shear horizontal (SH) wave propagating into a nematic liquid crystal cell is measured. To investigate the acoustic phase depending on the director angle of a liquid crystal, the two SH wave devices having different initial molecular orientations are fabricated. The acoustic phase change of the SH wave devices is measured for various applied electric fields. The numerical analyses are also performed by considering director distribution in the nematic liquid crystal layer. The experimental acoustic phase changes are well accorded with the calculated shear stresses as a viscous resistance.

DOI： 10.1080/15421400701686710

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掲載種別：研究論文（学術雑誌）  

Two types of microwave variable phase shifters of a coplanar waveguide with float electrodes on both sides and a float electrode on one side using ferroelectric liquid crystal are discussed. The measured phase shift is proportional to the frequency of the microwave according to the theory, and the measured phase in the both-sided-electrode device is larger than that in the one-sided-electrode device. The measured phase shift increases with increasing applied voltage in both devices. The response time of the both-sided-electrode device is less than 1 ms above 120V, and a very high speed variable phase shifter is realized.

DOI： 10.1080/15421400701684152

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掲載種別：研究論文（学術雑誌）  

We have investigated optical characteristics of a one-dimensional dual photonic crystal with helix. We have confirmed the particular defect mode at the band edges of CLC has high Q-factor. The defect mode with high Q-factor existed at any conditions regardless of the polarization of incident light, helical pitch and thickness of the CLC. All defect modes in the photonic band gap could be divided in two groups. The first one was the defect modes whose Q-factor became high at the long-wavelength edge of the CLC band. The other one was that at the short-wavelength edge of the CLC.

DOI： 10.1080/15421400701686595

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掲載種別：研究論文（学術雑誌）  

The Propagation characteristics of a shear horizontal (SH) wave in a trilayer structure having a viscous fluid layer is analyzed from a numerical analysis. Acoustic phase changes under application of electric fields in a nematic liquid crystal cell are measured using the SH wave. The acoustic phase advances with increasing the applied electric field. This result corresponds with the viscosity change based on a molecular reorientation of the liquid crystal. In dynamic response measurement, the response times in the phase and the optical measurements are different, because the measured area of the acoustic phase is only the vicinity of the glass surface.

DOI： 10.1080/15421400701686785

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掲載種別：研究論文（学術雑誌）  

We have investigated light localization in one-dimensional photonic crystal with a helix defect of ferroelectric liquid crystal (FLC) and experimentally observed particular defect mode peaks at the photonic band edge of FLC. The appearance of particular defect modes was confirmed by theoretical calculations. The single-mode laser action has been observed in the one-dimensional photonic crystal with a helix defect of FLC doped the laser dye. The single-mode laser action was observed at the edge wavelength of photonic band gap of FLC, which is based on a strong optical confinement into the FLC layer.

DOI： 10.1080/00150190600968371

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

The authors have investigated the optical characteristics of a one-dimensional hybrid photonic crystal (1D HPC) containing cholesteric liquid crystal (CLC) as a defect by theoretical calculation and predicted the appearance of additional modes at the band edges of the CLC defect, whose Q factor was higher than those of the other defect modes. They have confirmed the appearance of the additional mode experimentally. Single-mode laser action with low pumping threshold was observed in a 1D HPC with a dye-doped CLC defect, which is based on the additional defect mode with a high Q factor peculiar to the CLC defect having periodic structure. (c) 2006 American Institute of Physics.

DOI： 10.1063/1.2347114

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

We study a defect mode in a one-dimensional photonic band gap of a cholesteric liquid crystal (CLC) consisting of two helicoidal periodicities. The optical properties of this CLC are analyzed using 4x4 transfer matrix and finite difference time domain (FDTD) methods. In calculated transmission spectra of this CLC, one of the defect modes always appears at the band edge wavelength of the inner CLC having a different helix to that of two sides of CLCs. Furthermore, the electric field analysis of this CLC has also been demonstrated by the FDTD method. At the defect mode wavelength, the electric field enhancement is found to be significant larger than a normal CLC. (c) 2006 American Institute of Physics.

DOI： 10.1063/1.2215124

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掲載種別：研究論文（学術雑誌）  

Three-dimensional periodic structures of synthetic opals and various inverse opals with interconnected regular array of nano-scale voids in which liquids and liquid crystals can be infiltrated have been prepared for the study of liquids and liquid crystals confined in nano-scale spaces. One-dimensional periodic structure containing a defect layer in which liquids and liquid crystals can be introduced have also been prepared by the multi-layered SiO 2 and TiO2 stacks. These three-dimensional and one-dimensional periodic structures containing liquids and liquid crystals exhibited novel properties as tunable photonic crystals. Utilizing these phenomena a simple apparatus to evaluate the refractive index of liquids precisely have been proposed, with which sorts of dielectric liquids can be distinguished. Kerr effect and non-linear optical effects of liquids contained in the defect layer of the one-dimensional systems have also been discussed. When the opals and inverse opals contain liquid crystals, the transmission dip and reflection peak wavelengths can be tuned by applied field. The response characteristics are different for opals and inverse opals, which can be interpreted by taking the interaction of liquid crystal molecules with the inner surface of the void into consideration. Utilizing one-dimensional systems containing liquid crystals in the defect layer a ultra-fast switching of a laser light and also in systems containing liquid crystals and fluorescent dyes a voltage tunable lasing in the wide spectral range have been demonstrated. © 2006 IEEE.

DOI： 10.1109/TDEI.2006.1657984

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE SA  

The optical characteristics of cholesteric liquid crystal (ChLC) with multiple defect layers where pitch lengths were modified have been investigated. The transmission spectrum of such multi-defect ChLCs was simulated using the transfer matrix method. A transmission band appeared in the photonic band-gap (PBG) of the ChLC. The PBG displayed a shift as the periodicity of the defect sites was decreased. Finite difference time domain simulations have been carried out to investigate the electromagnetic field distributions within the medium. Obtained results showed that coupling between the modes confined in the defect layers lead to the formation of the defect band in the PBG. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tsf.2005.09.138

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE SA  

Low-threshold single-mode laser action in a one-dimensional double periodic structure which includes cholesteric liquid crystal (CLC) in the inorganic periodic structure as a defect has been observed. This laser action is based on the effect of double optical confinement in the inner helicoidal and the outer periodic structures. Theoretical calculations have been carried out to confirm the effect of effective double optical confinement in the double periodic structure. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tsf.2005.09.133

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

A nematic liquid crystal director orientation in a vicinity of a glass/liquid-crystal interface is investigated in relation to an acoustic phase change of a shear horizontal (SH) wave propagating in a cell structure. The relationships between phase change and electric field applied to the liquid crystal layer are given for various layer thicknesses. The numerical analysis of wave penetration in the liquid crystal cell is performed by considering distribution profiles of liquid crystal direction in relation to shear stress at the glass/liquid-crystal interface. The experimental acoustic phase changes are well consistent with the calculated shear stresses as flow resistance. The acoustic phase is strongly dependent on viscosity distribution and particle velocity in the liquid crystal layer.

DOI： 10.1143/JJAP.45.4662

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

We study a defect mode in a one-dimensional photonic band gap of a cholesteric liquid crystal (CLC) consisting of two helicoidal periodicities. The optical properties of this CLC are analyzed using 4 x 4 transfer matrix and finite difference time domain methods. One of the defect modes always appears at the band edge wavelength of the inside CLC. Furthermore, this CLC is fabricated using photopolymerized CLC films. The transmission spectrum of this CLC is observed experimentally. Some peaks appear in the one-dimensional photonic band gap of this CLC, and the experimental results agree well with the calculated.

DOI： 10.1143/JJAP.45.493

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記述言語：日本語   出版者・発行元：THE JAPANESE LIQUID CRYSTAL SOCIETY  

強誘電性液晶を用いた浮遊電極の付いたコプレーナ線路型のマイクロ波可変遅延線を構成し、その動作特性について検討した。強誘電性液晶に電圧を印加した時に位相変化が確認され、位相変化量は周波数に比例した。また、印加電圧を増加すると位相変化量も増加した。電圧の極性を反転した時の位相変化の応答時間は、電圧の増加とともに単調に減少し、120V以上の電圧で1ms以下という高速応答が実現されていることを確認した。

DOI： 10.11538/ekitou.2006.0.87.0

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記述言語：日本語   出版者・発行元：THE JAPANESE LIQUID CRYSTAL SOCIETY  

強誘電性液晶を用いたコプレーナ線路型マイクロ波可変遅延線を作製し、このデバイスにおいて計算により液晶駆動用電界の分布を求めた。これにより明らかになった電界分布及び液晶の配向状態から、マイクロ波可変遅延線の動作について解析した結果を報告する。

DOI： 10.11538/ekitou.2006.0.208.0

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記述言語：日本語   出版者・発行元：THE JAPANESE LIQUID CRYSTAL SOCIETY  

弾性波の1種であるＳＨ波(Shear horizontal wave)を用いることにより、界面近傍におけるネマティック液晶の配向状態の時間応答を測定するとともに、光波において液晶全体の配向状態の時間応答を測定し、これと比較した。

DOI： 10.11538/ekitou.2006.0.73.0

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Electrical tuning of the wavelength of a defect mode lasing in a one-dimensional photonic crystal has been demonstrated using a conducting polymer as an active emission layer and a nematic liquid crystal as an electrically tunable defect layer in the periodic structure. Lasing wavelength is widely tuned upon applying the electric field, which follows a defect mode shift due to the refractive index change in the nematic liquid crystal defect layer caused by field-induced realignment of the liquid crystal molecules.

DOI： 10.1080/15421400590957738

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SCRIPTA TECHNICA-JOHN WILEY & SONS  

It is possible by the application of voltage to control the local level in a one-dimensional photonic crystal with a liquid crystal defect layer. In the present paper, a nematic liquid crystal is used and high-speed switching is attempted on the basis of the shift of the localized state wavelength by the photonic bandgap and liquid crystal orientation control. First, by the finite-difference time-domain method, the optical propagation characteristics inside a one-dimensional photonic crystal with a liquid crystal defect layer are analyzed. It is shown that optical switching by control of the localized state wavelength is possible. TiO2 and SiO2 are periodically laminated as a one-dimensional photonic crystal. A nematic liquid crystal layer is introduced as a defect layer to disturb the periodicity, resulting in a one-dimensional photonic crystal with a liquid crystal defect layer. By application of a voltage, the orientation of the liquid crystal defect layer is varied in an attempt to perform optical switching by electric field control of the localized state. High-speed optical switching of microsecond order is successful with nematic liquid crystals. (c) 2005 Wiley Periodicals, Inc.

DOI： 10.1002/ecjb.20087

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

Laser action in a one-dimensional photonic crystal (PC) with dye-doped cholesteric liquid crystals as a defect layer has been investigated. A single-mode lasing has been achieved in the PC with a helical structure, which is based on the defect mode of the PC with a defect and the band edge effect of the cholesteric helix. The contribution of the interaction between the defect mode and band edge effects to the laser action was confirmed on the basis of the helix pitch dependence of lasing characteristics. The threshold of the laser action in the PC with the helical structure was lower than that in the helical structure without a PC. It has also been found that lasing wavelength shifts as a function of temperature corresponding to the band edge shift of the cholesteric liquid crystal.

DOI： 10.1143/JJAP.44.L629

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Electrical tuning of defect modes in a one-dimensional (1D) photonic crystal (PC) has been demonstrated using a ferroelectric liquid crystal (FLC) and a nematic liquid crystal (NLC) defect layers in the periodic structure. The transmission peak intensities for defect mode depends on the angle between LC molecular axis and polarization direction of the incident light. At defect mode wavelength, the 1D PC with LC defect layer transmits only the light with the polarization direction determined by the direction of extraordinary or ordinary optical axes in LC defect. Polarization direction of the light propargating through the 1D PC with in-plane NLC defect can be controlled based on field-induced in-plane realignment of NLC molecules.

DOI： 10.1080/15421400590957792

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Electrical tuning of a wavelength of a defect mode lasing in a one-dimensional periodic structure has been demonstrated using a dye-doped nematic liquid crystal as a defect layer in the periodic structure. Lasing wavelength is widely tuned upon applying the electric field, which is due to the refractive index change in the defect layer caused by the field-induced realignment of the liquid crystal molecules.

DOI： 10.1080/154214091009563

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

A defect mode in a one-dimensional (1D) photonic crystal (PC) with an in-plane switchable nematic liquid crystal (NLC) as a defect layer has been investigated. Two types of defect modes appear in the photonic band gap of the transmission spectrum. They are associated with the extraordinary and ordinary refractive indices of the NLC in the defect aligning perpendicular to the propagation direction of the light. The defect mode position does not shift upon the in-plane reorientation of the NLC molecules, but the peak intensity changes with rotating the director of the NLC around the light propagating axis. On the basis of these defect modes, the polarization direction of the light passing through the ID PC with the in-plane switchable NLC can be electrically controlled by changing the field direction in the defect layer.

DOI： 10.1143/JJAP.43.L1477

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掲載種別：研究論文（国際会議プロシーディングス）  

Various types of tunable lasing in dye-doped liquid crystals with one dimensional periodic structure have been demonstrated. An electrical tuning of lasing wavelength has been demonstrated in a dye-doped chiral smectic liquid crystal mixture with a short pitch helical structure which is so-called ferroelectric liquid crystal (FLC). Waveguide configuration of FLC laser has also been proposed, also in which the lasing wavelength widely can be tuned upon the electric filed. The electrically tunable lasing has been observed also in a focal conic structure of dye-doped cholesteric liquid crystal. This laser action is based on a helix micro-cavity in focal conic domains. Optically pumped distributed feedback lasing has been proposed in a dye-doped nematic liquid crystal (NLC) waveguide by holographic excitation, in which continuous tuning of the lasing wavelength is performed upon applying electric filed. Electrical tuning of the wavelength of the defect mode lasing in a one-dimensional periodic structure has been demonstrated using a dye-doped NLC as a defect layer in the periodic structure. Lasing wavelength is widely tuned upon applying the electric field, which is due to the refractive index change in the defect layer caused by the field-induced realignment of the NLC molecules.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-V C H VERLAG GMBH  

Tunability of optical properties such as transmission and reflection by temperature and applied voltage has been demonstrated in synthetic opals and inverse opals like three-dimensional photonic crystals infiltrated with liquid crystals, conjugated molecules and polymers, in accordance with theoretical calculation. A new type of tunability based on uncoupled mode in a two-dimensional photonic band gap influenced by the field-dependent anisotropy in liquid crystals has also been demonstrated theoretically. Spectral narrowing and lasing have been observed in these opals infiltrated with conducting polymers and fluorescent dyes like three-dimensional photonic crystal and fluorescent dye-doped cholesteric and ferroelectric liquid crystal as one-dimensional photonic crystal. These lasing wavelength can be controlled by the applied voltage. Laser emission was also realized with conducting polymer on a surface relief grating formed on an azo-polymer film by interference optical beam.

DOI： 10.1002/masy.200450817

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

Electrical tuning of the wavelength of the defect mode lasing in a one-dimensional photonic crystal has been demonstrated using a conducting polymer as an active emission layer and a nematic liquid crystal as an electrically tunable defect layer in the periodic structure. Lasing wavelength is widely tuned upon applying the electric field, which follows a defect mode shift due to the refractive index change in the nematic liquid crystal defect layer caused by field-induced realignment of the liquid crystal molecules. (C) 2004 American Institute of Physics.

DOI： 10.1063/1.1686891

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人電子情報通信学会  

液晶欠陥層を有する1次元フォトニック結晶は, 電圧印加によって局在準位の制御が可能である. 本論文ではネマチック液晶を用, いて, フォトニックバンドギャップと液晶配向制御による局在準位波長のシフトに基づく高速光スイッチングを試みた. まず, 時間領域差分法により, 液晶欠陥層を有する1次元フォトニック結晶内部の光伝搬特性を解析し, 局在準位波長制御による光スイッチングが可能であることを明らかとした. 実際に, 1次元フォトニック結晶としてTiO_2とSiO_2を周期的に積層させ, その周期性を乱ず欠陥層とし七, ネマチック液晶欠陥層を導入して, 液晶欠陥層を有する1次元フォトニック結晶を作製した. 電圧印加によって液晶欠陥層の配向を変化させ, 局在準位の電界制御による光スイッチを試み, ネマチック液晶を用いたマイクロセカンドオーダの高速光スイッチングに成功した.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：SPIE-INT SOC OPTICAL ENGINEERING  

Optically pumped laser action has been observed at the edge wavelength of the stop band in a dye-doped flexible freestanding film of photopolymerized cholesteric liquid crystal (PCLC), which originates from band edge effect of the one-dimensional photonic band gap. On the other hand, defect mode laser action has also been experimentally demonstrated at the defect mode wavelength within the band gap. This laser action is based on the photon localization at the twist defect of the composite film consisting of two PCLC layers. Twist defect mode (TDM) is induced by the introduction of twist defect which is a discontinuity of the director rotation around the helix axis at an interface of two PCLC layers. We also propose a new type of tunable defect mode based on the chiral defect in which the partial modulation of the helix pitch is introduced.

DOI： 10.1117/12.555543

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Optically pumped mirrorless laser action has been observed in a dye-doped photopolymerized cholesteric liquid crystal (PCLC) polymer film. At high excitation energy above the threshold, the laser action is observed at an edge of the one-dimensional photonic band of the PCLC herical structure. This PCLC film possesses a mechanical flexibility, and laser action is observed even in a bent film. The helical pitch of the PCLC polymer has no temperature dependence, which is favorable for the laser device application.

DOI： 10.1080/15421400490439211

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Optically pumped mirrorless laser action has been observed in a dye-doped photopolymerized cholesteric liquid crystal CPCLC) polymer film At high excitation energy above the threshold, the laser action is observed at an edge of the one-dimensional photonic band of the PCLC herical structure. This PCLC film possesses a mechanical flexibility, and laser action is observed even in a bent film. The helical pitch of the PCLC polymer has no temperature dependence, which is favorable for the laser device application.

DOI： 10.1080/15421400490439211

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SCRIPTA TECHNICA-JOHN WILEY & SONS  

A liquid crystal defect layer is introduced into one-dimensional photonic crystal and its optical distance is varied by an electric field so that the defect mode can be controlled. An optical propagation simulation is carried out for study of optical characteristics in a model in which nematic liquid crystal is introduced as a liquid crystal defect layer in a dielectric multilayer as a one-dimensional photonic crystal. We investigate whether the defect mode can be controlled by varying the optical length by way of change in orientation of the-liquid crystal molecules. Based on the simulation results, a device is fabricated with a nematic defect layer introduced within a SiO2/TiO2 laminated periodic structure. The defect mode of the one-dimensional photonic crystal is measured. It is confirmed that the experimental results and the simulation results agree well. Further, it is successful in shifting the defect mode wave-length by applying a voltage. Hence, it is clear that the defect mode can be, modulated by changing the optical length of the defect layer by means of control of the orientation of the liquid crystal molecules by an applied voltage. (C) 2004 Wiley Periodicals, Inc.

DOI： 10.1002/ecjb.10167

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TAYLOR & FRANCIS LTD  

Electrical tuning of defect modes in a one-dimensional photonic crystal has been demonstrated using a ferroelectric liquid crystal and a nematic liquid crystal as a defect layer in the periodic structure. The theoretical calculation based on a simple transfer matrix has been carried out, and the result has been found to agree with the experimental result. A high-speed electrooptic switching based on the tunable defect mode has also been demonstrated. The response time of the order of several tens microseconds in this defect mode switching has been realized at low driving voltage.

DOI： 10.1080/00150190490511554

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

The focus of acoustic partial discharge measurements is based on the discharge location. The tank wall thickness of a power transformer is usually larger than the wavelength of the signal, and therefore possesses a path for the signal, thereby complicating the triangulation procedure for the determination of the discharge location. Owing to their difference in frequency, the signals that travel faster through the mixed path of oil and tank and the slower ones that follow a direct path through oil can be differentiated. By using wavelet transform, we are able to not only discriminate between these two signals, but also to determine the exact instant at which a change in the detected signal occurs due to their interference. This is a new method of analyzing the partial discharge acoustic signal to extract the signal that travels through the direct path in oil and can lead to a more accurate discharge location.

DOI： 10.1143/JJAP.42.5347

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

The focus of acoustic partial discharge measurements is based on a partial discharge source location, and therefore knowledge of the acoustic signal propagation path is important. Numerical simulation of wave propagation in a model transformer is carried out to aid in the interpretation of the laboratory measurements in as far as the delay time of the various peaks is concerned. The simulated signals and the experimentally measured signals are in good agreement. We are able to determine the signal propagation path and to explain the waveform profile depending on the position of the acoustic emission sensors attached to the model transformer tank wall. The numerical simulation is carried out by solving the three dimensional (3D) wave equation using the finite-difference method. Of particular interest are the boundary conditions and choice of grid size to minimize the dispersion error.

DOI： 10.1143/JJAP.42.3686

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

High-speed electrooptic switching based on the tunable defect mode in a one-dimensional photonic crystal containing a nematic liquid crystal defect layer has been demonstrated. The response time of the order of microseconds in this defect mode switching has been realized at low voltage. This high-speed switching originates from the narrow spectral linewidth of the The decay time is also of the defect mode. With increasing applied voltage V, the rise time decreases in proportion to V-2 order of several tens of microseconds.

DOI： 10.1143/JJAP.42.L669

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

The twist defect mode (TDM) has been experimentally demonstrated in the transmission spectrum of a composite film consisting of two photopolymerized cholesteric liquid crystal (PCLC) layers. The self-organized helical structure of PCLC acts as a one-dimensional (I-D) photonic crystal, and the twist defect which is a discontinuity of the director rotation around the helix axis at an interface of two PCLC layers, induces the TDM. Optically pumped laser action based on the TDM has also been observed in a dye-doped double composite PCLC film. At a high excitation energy above the threshold, the laser action has been observed at the TDM wavelength in the middle of the I-D photonic band gap of the PCLC helical structure.

DOI： 10.1143/JJAP.42.L472

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

Electrical tuning of the wavelength of the defect-mode lasing in a one-dimensional periodic structure has been demonstrated using a dye-doped nematic liquid crystal as a defect layer in the periodic structure. Lasing wavelength is widely tuned upon applying an electric field, which is due to the refractive index change in the defect layer caused by the field-induced realignment of the liquid crystal molecules. (C) 2003 American Institute of Physics.

DOI： 10.1063/1.1577829

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

The wavelength of the laser action based on a defect mode in a one-dimensional periodic structure has been electrically controlled using a dye-doped nematic liquid crystal as a defect layer. The lasing wavelength is widely tuned upon the applying electric field, which originates from the refractive index change in the defect layer caused by the field-induced realignment of the liquid crystal molecules.

DOI： 10.1109/ICPADM.2003.1218470

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INST PURE APPLIED PHYSICS  

Electrical tuning of defect modes in a one-dimensional periodic structure has been demonstrated using a nematic liquid crystal as a defect layer in the periodic structure. The wavelength of the defect mode shifts upon applying the electric field, which is due to the refractive index change in the defect layer caused by the field-induced realignment of the liquid crystal molecules. The theoretical calculation based on a simple transfer matrix has been carried out, and the result has been found to agree with the experimental result.

DOI： 10.1143/JJAP.41.L1482

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

Optically pumped mirrorless laser action has been observed in a dye-doped flexible free-standing film of photopolymerized cholesteric liquid crystal (PCLC). In the PCLC film, self-organized helical structure acts as one-dimensional (1D) photonic crystal. At high excitation intensity above the threshold, a laser action is observed at an edge of the 1D photonic band of the PCLC helical structure. This PCLC film laser possesses an excellent mechanical flexibility, and the laser action is also observed in a bent film of PCLC. This implies that the one-dimensional periodic structure for the laser action is maintained even in the deformed film. Using such flexibility of the PCLC film, a focusing effect of laser emission is demonstrated in a circularly deformed film. Moreover, the helical pitch of the PCLC has no temperature dependence in contrast to that of unpolymerized cholesteric liquid crystal. This means that the operation wavelength of laser action is thermally stable, which is the great advantage for the device application. (C) 2002 American Institute of Physics.

DOI： 10.1063/1.1522498

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER INST PHYSICS  

Optically pumped mirrorless laser action has been observed in a dye-doped flexible free-standing film of photopolymerized cholesteric liquid crystal (PCLC). In the PCLC film, self-organized helical structure acts as one-dimensional (1D) photonic crystal. At high excitation intensity above the threshold, a laser action is observed at an edge of the 1D photonic band of the PCLC helical structure. This PCLC film laser possesses an excellent mechanical flexibility, and the laser action is also observed in a bent film of PCLC. This implies that the one-dimensional periodic structure for the laser action is maintained even in the deformed film. Using such flexibility of the PCLC film, a focusing effect of laser emission is demonstrated in a circularly deformed film. Moreover, the helical pitch of the PCLC has no temperature dependence in contrast to that of unpolymerized cholesteric liquid crystal. This means that the operation wavelength of laser action is thermally stable, which is the great advantage for the device application. (C) 2002 American Institute of Physics.

DOI： 10.1063/1.1522498

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

In this paper, we present a three-dimensional numerical simulation of partial discharge (PD) acoustic wave propagation that has been developed to provide time-domain signal representation in a model transformer. The numerical modeling of acoustic PD data is used to support interpretations of laboratory experimental data and to enhance the understanding of acoustic wave propagation in a structure like the power transformer, and hence PD source location in the same. It is intended that an extension of the work presented here, to account for real transformer geometry and also to visualize the propagation of acoustic wave fronts, will later be compared with field results. The three-dimensional wave equation, given by c(2)del(2)P=partial derivative(2)P/partial derivativet(2), where c is the acoustic velocity and P the pressure wave field, defines an initial value problem and describes time evolution. The goal of the numerical code is to track that time evolution with some desired accuracy taking into consideration the boundary conditions that govern the evolution in time of points on the boundary of the spatial region of interest. This is particularly important for the satisfactory modeling of a complex structure like power transformer. In solving the above equation using finite-difference method, of particular interest are the conditions of numerical stability. In this paper we apply the stability analysis method originally developed by Von Neumann. The simulation results are in agreement with the results obtained from the laboratory experiments.

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掲載種別：研究論文（国際会議プロシーディングス）  

The location of partial discharge is tried using the ultrasonic wave of partial discharge. At present, the experiment is carried out in the simple model of the transformer. Peaks of the simulated ultrasonic wave appeared in the time which was almost equal to peaks of actual ultrasonic wave. And, the ratio of the amplitude of the ultrasonic wave was also almost in agreement. The simulation was able to reproduce the ultrasonic wave by partial discharge in two dimensions. The experimental system was simulated, and the transmission was confirmed in two dimensions.

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掲載種別：研究論文（国際会議プロシーディングス）  

Many researchers have studied the Partial Discharge (PD) source location in transformers using acoustical methods. However, most of these studies have treated the transformer as a homogeneous medium, thus rendering the location of discharges inside the transformer winding difficult. In this paper we present a 3-D computer simulation of the PD acoustic signal propagation path in an attempt to locate the PD source. The computer simulation is in agreement with experimental data obtained from the laboratory. Further, the effect of the real transformer tank on the acoustic signal is studied with an aim of distinguishing the various frequency dependent signal components that are detected by the Acoustic Emission (AE) sensor. This is particularly important in explaining the acoustic coupling between oil and transformer tank material and for determining the propagation velocities when determining the PD source location.

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記述言語：日本語   出版者・発行元：電気学会  

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記述言語：日本語   出版者・発行元：一般社団法人 日本液晶学会  

Photonic crystals show the photonic band gap which prohibits propagation of the photon in a certain energy range. Multi-bilayered films are known as one dimensional photonic cystals having optical periodicity with different refractive indices. Multi-bilayered films reflect light of specific wavelength, and the reflection wavelength is related to the film thickness and refractive indices of each materials. In this study, we investigated the structure effect of azobenzene polymer on out-of-plane molecular orientation behavior, and reported switching of molecular orientation in one dimensional photonic crystal.

DOI： 10.11538/ekitou.2015.0__3C02

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記述言語：日本語   出版者・発行元：一般社団法人 日本液晶学会  

&lt;p&gt;Multilayer films are known as one dimensional photonic crystals (1DPC), as the specific wavelength of light is reflected according to bragg diffraction equation. In the photonic band edge of 1DPC, group velocity of photon decreases remarkably, so that the population inversion is easily caused when the medium in PC is excited. Therefore, the low threshold laser emission is induced. In this study, we fabricated the dye-doped multilayer film containing azobenzene polymer as defect layer, and we discussed laser emission by the change in the molecular orientation of the azobenzene groups.&lt;/p&gt;

DOI： 10.11538/ekitou.2014.0_PB16

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記述言語：日本語  

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記述言語：日本語   出版者・発行元：一般社団法人 日本液晶学会  

Multi-bilayered films consisting of two stacked materials with different refractive indices reflect specific wavelength of light. It was found that multi-bilayered films having larger thickness ratio of two stacked materials reflect not only primary reflection but also high order reflection by simulation. In this study, we fabricated high order reflection multi-bilayered films by spin-coating method, and discussed about the optical properties. Furthermore, ON/OFF switching of the reflection was investigated by introducing azobenzene liquid crystal polymer into the multi-bilayered films.

DOI： 10.11538/ekitou.2013.0__PA29

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記述言語：日本語  

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

マイクロストリップライン構造における誘電体部分に液晶を装荷したマイクロ波帯液晶装荷マイクロストリップライン(MSL)移相器の誘電率変化,すなわち誘電異方性(Δε)と可変位相量および応答時間の理論計算を行った.MSL中の液晶配向の空間分布は,液晶の連続体理論に基づき計算しており,液晶配向分布とMSLの基本モードの高周波電界を用いて液晶装荷MSL移相器の実効誘電率および応答時間を求めている.さらに,液晶装荷MSL移相器の中心導体幅および液晶層厚の違いが誘電率変化および応答時間に及ぼす影響等を理論計算より考察し,特性インピーダンス50Ωの液晶装荷MSL移相器を試作し,実験値と理論値を比較した結果,5%誤差以内良い一致を得ている.

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

コプレーナ線路に浮遊電極を配した伝送線路(CPW-FE)に液晶を装荷したマイクロ波帯液晶装荷移相器の誘電率変化すなわち誘電異方性(Δε)の理論計算を行った.CPW-FE中の液晶配向の空間分布は,液晶の連続体理論に基づき計算しており,液晶配向分布とCPWの基本モードの高周波電界を用いてCPW-FEの実効誘電率を求めている.また,液晶駆動用電圧の印加方向の変化に伴う実効誘電率の変化すなわち誘電異方性の実験値と計算値の比較では,位相変化量の印加電圧依存は定性的に良い一致を得ている.さちに液晶配向分布とCPWの高周波電界分布を用いて,CPW-FEの中心導体幅等の構造の違いが誘電率変化に及ぼす影響等を考察している.

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

コプレーナ線路に浮遊電極を配した伝送線路(CPW-FE)に液晶を装荷したマイクロ波帯液晶装荷移相器の誘電率変化すなわち誘電異方性(Δε)の理論計算を行った.CPW-FE中の液晶配向の空間分布は,液晶の連続体理論に基づき計算しており,液晶配向分布とCPWの基本モードの高周波電界を用いてCPW-FEの実効誘電率を求めている.また,液晶駆動用電圧の印加方向の変化に伴う実効誘電率の変化すなわち誘電異方性の実験値と計算値の比較では,位相変化量の印加電圧依存は定性的に良い一致を得ている.さちに液晶配向分布とCPWの高周波電界分布を用いて,CPW-FEの中心導体幅等の構造の違いが誘電率変化に及ぼす影響等を考察している.

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

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記述言語：英語  

DOI： 10.1016/S1574-0641(07)80030-1

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記述言語：英語   出版者・発行元：超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会  

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記述言語：日本語   出版者・発行元：超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会  

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記述言語：日本語   出版者・発行元：日本液晶学会  

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記述言語：英語   出版者・発行元：一般社団法人電子情報通信学会  

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開催年月日： 2022年7月

記述言語：英語   会議種別：ポスター発表  

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開催年月日： 2022年6月

記述言語：英語   会議種別：口頭発表（招待・特別）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語  

マイクロストリップライン構造における誘電体部分に液晶を装荷したマイクロ波帯液晶装荷マイクロストリップライン(MSL)移相器の誘電率変化,すなわち誘電異方性(Δε)と可変位相量および応答時間の理論計算を行った.MSL中の液晶配向の空間分布は,液晶の連続体理論に基づき計算しており,液晶配向分布とMSLの基本モードの高周波電界を用いて液晶装荷MSL移相器の実効誘電率および応答時間を求めている.さらに,液晶装荷MSL移相器の中心導体幅および液晶層厚の違いが誘電率変化および応答時間に及ぼす影響等を理論計算より考察し,特性インピーダンス50Ωの液晶装荷MSL移相器を試作し,実験値と理論値を比較した結果,5%誤差以内良い一致を得ている.

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会議種別：ポスター発表  

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記述言語：日本語  

二次元フォトニック結晶に液晶を導入した系において、負の屈折角の制御が可能であることが武田らによって報告されている。今回、我々は、彼らが検討したバンドよりもさらに高次のバンドにおいて、非常に狭い周波数領域ではあるが、液晶の配向変化によって、フォトニック結晶の実効屈折率の値を正から負へと変化させることが可能な特異な周波数領域が存在することを数値計算から見出した。

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記述言語：英語   会議種別：ポスター発表  

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会議種別：口頭発表（一般）  

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記述言語：日本語  

コプレーナ線路に浮遊電極を配した伝送線路(CPW-FE)に液晶を装荷したマイクロ波帯液晶装荷移相器の誘電率変化すなわち誘電異方性(Δε)の理論計算を行った.CPW-FE中の液晶配向の空間分布は,液晶の連続体理論に基づき計算しており,液晶配向分布とCPWの基本モードの高周波電界を用いてCPW-FEの実効誘電率を求めている.また,液晶駆動用電圧の印加方向の変化に伴う実効誘電率の変化すなわち誘電異方性の実験値と計算値の比較では,位相変化量の印加電圧依存は定性的に良い一致を得ている.さちに液晶配向分布とCPWの高周波電界分布を用いて,CPW-FEの中心導体幅等の構造の違いが誘電率変化に及ぼす影響等を考察している.

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会議種別：ポスター発表  

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記述言語：日本語  

強誘電性液晶を用いたコプレーナ線路型のマイクロ波ミリ波可変位相器において、デバイスの実効誘電率はデバイスの効率を考える指標となる。本研究においては、デバイスの構造を変化させた時の実効誘電率についてマイクロ波シミュレータを用いて計算した高周波電界分を用い、様々な構造における実効誘電率を計算し、効率の良いデバイス構造について検討している。

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会議種別：口頭発表（一般）  

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記述言語：日本語  

コプレーナ線路に浮遊電極を配した伝送線路(CPW-FE)に液晶を装荷したマイクロ波帯液晶装荷移相器の誘電率変化すなわち誘電異方性(Δε)の理論計算を行った.CPW-FE中の液晶配向の空間分布は,液晶の連続体理論に基づき計算しており,液晶配向分布とCPWの基本モードの高周波電界を用いてCPW-FEの実効誘電率を求めている.また,液晶駆動用電圧の印加方向の変化に伴う実効誘電率の変化すなわち誘電異方性の実験値と計算値の比較では,位相変化量の印加電圧依存は定性的に良い一致を得ている.さちに液晶配向分布とCPWの高周波電界分布を用いて,CPW-FEの中心導体幅等の構造の違いが誘電率変化に及ぼす影響等を考察している.

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記述言語：日本語  

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会議種別：口頭発表（一般）  

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記述言語：日本語  

液晶分子が螺旋構造を有するコレステリック液晶はプラナー配向状態において、その周期を調節することにより可視領域の光を反射光として観察することができる。しかし、セル厚が大きくなると配向が乱れてしまうという問題がある。そこで超音波を利用して液晶中に流動を起こすことにより、液晶分子に再配向するきっかけを与え、比較的大きなセル厚を持つコレステリック液晶でも配向を可能とした。

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会議種別：口頭発表（一般）  

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記述言語：日本語  

1次元フォトニック結晶にネマティック液晶欠陥層を導入することで、液晶分子の異常光屈折率および常光屈折率に対応した波長において、分子長軸および短軸方向に偏光した欠陥モードが発現することがしられている。本研究ではその現象を用いて、パターン配向処理を施した液晶欠陥層を導入し、偏光制御素子の作製を試みた。

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会議種別：口頭発表（一般）  

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記述言語：日本語  

色素を添加したコレステリック液晶に電界を印加し、フィンガープリント構造を形成させた。それを光励起することにより、ストップバンド端においてレーザー発振が観測された。また、印加電界強度を変化させることにより螺旋ピッチを伸縮させ、レーザー発振波長を連続的に変化させることに成功した。さらに、コレステリック液晶に誘電体多層膜を付加させると、光を2次元的に閉じこめられることからレーザー発振閾値の低下が観測された。

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会議種別：口頭発表（一般）  

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記述言語：日本語  

強誘電性液晶を用いた浮遊電極の付いたコプレーナ線路型のマイクロ波可変遅延線を構成し、その動作特性について検討した。強誘電性液晶に電圧を印加した時に位相変化が確認され、位相変化量は周波数に比例した。また、印加電圧を増加すると位相変化量も増加した。電圧の極性を反転した時の位相変化の応答時間は、電圧の増加とともに単調に減少し、120V以上の電圧で1ms以下という高速応答が実現されていることを確認した。

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会議種別：口頭発表（一般）  

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会議種別：口頭発表（一般）  

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記述言語：日本語  

強誘電性液晶を用いた浮遊電極の付いたコプレーナ線路型のマイクロ波可変位相器を構成した。強誘電性液晶に電圧を印加した時の位相変化量は周波数に比例した。また、印加電圧を増加すると位相変化量も増加し、位相変化の応答時間は全電圧範囲で1.6ms以下という高速応答が実現されていることを確認した。また、このコプレーナ線路におけるマイクロ波電界分布を計算することにより、液晶の誘電異方性についての検討を行った。

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会議種別：口頭発表（一般）  

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記述言語：日本語  

我々は、これまでに簡便な液晶の粘性異方性の測定法として、弾性表面波型デバイスを用いた粘性測定を提案してきた。本手法では、圧電セラミックスで励振した弾性波を液晶セルのガラス基板中に伝搬させ、弾性波の伝搬速度が液晶の粘性に依存することを利用する。今回は、液晶粘性変化に伴う、弾性波の伝搬位相の定量的な解析を行ったのでそれを報告する。

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会議種別：口頭発表（一般）  

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記述言語：日本語  

一次元フォトニック結晶中にネマチック液晶欠陥層を導入し、局在準位を利用したスイッチングの時間応答解析を行い、実験結果と比較検討した。

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会議種別：ポスター発表  

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記述言語：日本語  

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会議種別：ポスター発表  

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記述言語：日本語  

弾性波の1種であるＳＨ波(Shear horizontal wave)を用いることにより、界面近傍におけるネマティック液晶の配向状態の時間応答を測定するとともに、光波において液晶全体の配向状態の時間応答を測定し、これと比較した。

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記述言語：日本語  

強誘電性液晶を用いたコプレーナ線路型マイクロ波可変遅延線を作製し、このデバイスにおいて計算により液晶駆動用電界の分布を求めた。これにより明らかになった電界分布及び液晶の配向状態から、マイクロ波可変遅延線の動作について解析した結果を報告する。

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会議種別：口頭発表（一般）  

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記述言語：日本語  

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会議種別：ポスター発表  

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記述言語：日本語  

We have carried out numerical calculations on cholesteric liquid crystals in which defect layers with a different pitch length have been introduced periodically. Our Transfer Matrix Method and Finite Difference Time Domain calculations showed that a transmittance band appears in the Photonic Band Gap (PBG) of the material, when defect layers of sufficient width are introduced. The tunability of the transmittance band was realized by changing the degree of modulation or the defect layer width. Upon introduction of thin defect layers, which are characteristic of the pitch modulation defects, we realized a shift in the PBG itself.

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会議種別：ポスター発表  

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記述言語：日本語  

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会議種別：口頭発表（一般）  

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記述言語：日本語  

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会議種別：口頭発表（一般）  

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会議種別：ポスター発表  

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記述言語：日本語  

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会議種別：ポスター発表  

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強誘電性液晶自己保持膜に交流電界を印加すると、分子が電界に対して応答し、その際に生じる微小な振動は特定の周波数において振動強度が増大することが報告されている。この電界誘起振動を、レーザドップラ振動計を用いて調べ、自己保持膜の振動の振幅及び面内分布を測定した結果から解析した結果について報告する。

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会議種別：ポスター発表  

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ダイレクタベクトルがある一定の周期を持ち、左巻きもしくは右巻きに自己組織的な構造をとるコレステリック液晶は、偏光選択性をもつフォトニック結晶として近年注目を集めている。コレステリック液晶中に特有の構造欠陥として、ピッチ長の局所的な変調が上げられるが、そのような欠陥を媒質中に複数導入した場合、欠陥の導入の方法によりチューニング可能な光学特性の変化が予測できるので、それらについて報告する。

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記述言語：日本語  

We have adopted the finite domain time difference (FDTD) method to analyze the electro-magnetic field distribution of light propagating through a choleresteric liquid crystal (CLC) layer. FDTD calculation is a method used widely in the area of telecommunication to investigate electro-magnetic (EM) field distribution, and is based on solving the Maxwell Equation numerically by converting differentiations to simple differences over a small discrete period of time and distance. We have demonstrated the electric field distribution of selective reflection of light as well as a standing wave occurring at the band-edge wavelength of a CLC medium. It has been confirmed that FDTD calculation is a powerful tool for investigating the EM field distribution upon time and space propagation.

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会議種別：ポスター発表  

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記述言語：日本語  

A one-dimensional photonic crystal with conducting polymer and nematic liquid crystal as a defect layer has been studied. Upon applying electric field, the defect mode wavelength in the photonic band gap can be controlled by the reorientation of the liquid crystal molecules. Furthermore laser action at the localized state in the band gap has been observed, and the lasing wavelength was controlled upon applying the electric field.

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会議種別：口頭発表（一般）  

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圧電磁器薄膜で励振したSH波をガラス基板中に伝播させ、SH波の位相速度が液晶のダイレクタの配向角に依存することを利用して、基板界面近傍のネマチック液晶の配向が評価できることをこれまで報告している。本研究では、異なる厚さのセルにおけるネマチック液晶の配向について測定した結果を報告する。

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会議種別：ポスター発表  

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一次元フォトニック結晶中に螺旋周期構造を有するコレステリック液晶を導入した複合型フォトニック結晶の光学特性及びレーザー発振について研究を行った。複合型フォトニック結晶の透過スペクトルを調べた結果、コレステリック液晶のバンド端において、Q値の大きい局在準位ピークが、実験及び計算の両面から確認された。この素子を光励起すると、Q値の大きい局在準位に基づくシングルモード・レーザー発振が観測された。

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会議種別：ポスター発表  

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記述言語：日本語  

The photonic defect modes in a cholesteric liquid crystal induced by a local deformation of its helix has been investigated. The defect modes appear in transmission spectra only when incident circularly polarized light has the same handedness as the helix. The tuning of defect mode position can be performed upon both local expansion and squeeze of helix, in which the shift direction of the defect mode wavelength is opposite. Upon controlling the degree of the deformation of helix, continuous shift of defect modes can be realized.

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