著者

Morimoto Masahiro Koshiba Yasuko Misaki Masahiro Ishida Kenji

出版者

Institute of Physics

雑誌

Appl. Phys. Express (ISSN:18820778)

巻号頁・発行日

vol.8, no.10, 2015-10-01

被引用文献数

12

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We have investigated the temperature dependence of the piezoelectric coefficients and infrared sensor performance of spin-coated thin films of polyundecylurea (PUA11). The piezoelectric coefficients of the PUA11 films remained constant at temperatures above 180 °C and these films demonstrated thermal resistance superior to those of poly(vinylidene fluoride/trifluoroethylene) [P(VDF/TrFE)] films. The infrared sensor performance of the PUA11 films was measured after annealing at 125 °C for 500 h and was found to have retained 84% of its preannealing level. The thermal stability of the PUA11 films was higher than that of the P(VDF/TrFE) films; moreover, PUA11 is also expected to have superior electrothermal stability.

著者

Sugano Koji Suekuni Keisuke Takeshita Toshimitsu Aiba Kiyohito Isono Yoshitada

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.54, no.6, 2015-05-28

被引用文献数

11

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A micro/nanofluidic device containing linearly arranged gold nanoparticles embedded in nanochannels was developed for highly sensitive and highly efficient surface-enhanced Raman spectroscopy (SERS). The Si nanochannel array was fabricated using a photolithography-based process. The nanochannel width was controlled from 100 to 400 nm. Synthesized particles of mean diameter 100 nm were arranged linearly in the nanochannels, using a nanotrench-guided self-assembly process. We developed a process for integrating linearly arranged nanoparticles and micro/nanofluidic components. The particle geometry provided significant Raman enhancement. Furthermore, efficient Raman analysis was possible by scanning a laser spot, because the particles were arranged in one direction. The fabricated structures were evaluated for SERS using 4,4′-bipyridine molecules at concentrations of 1 mM and 10 µM. The Raman peaks was obtained from a few hot spots. The Raman spectra showed that the molecule-specific Raman intensities were correlated with the number of hot spots in the nanochannel.

著者

Morimoto Masahiro Koshiba Yasuko Misaki Masahiro Ishida Kenji

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.54, no.4, 2015-03-27

被引用文献数

8

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We have investigated the pyro- and piezoelectric properties of polyurea spin-coated films with thermal and chemical stability and their performance as infrared sensors. The piezoelectric coefficient d<inf>33</inf>was measured by a laser Doppler vibrometer to be 23.5 pC/N. This coefficient increased with the poling electric field up to around 75 MV/m, suggesting that the polyurea dipole is aligned by applying an electric field greater than 75 MV/m. When a triangular thermal wave was applied, a square-wave pyroelectric current was observed and the pyroelectric coefficient measured to be 5.11 µC/(m²·K). The infrared sensor performance of the polyurea thin film was examined by measuring the voltage sensitivity to infrared irradiation. The obtained result of 70.4 V/W at 1 Hz is consistent with the results calculated from the measured pyroelectric coefficient. Our findings suggest that the performance of the sensor may be improved by increasing the pyroelectric coefficient of the polyurea films.

著者

Ozaki Toshihiro Hirose Tetsuya Tsubaki Keishi Kuroki Nobutaka Numa Masahiro

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.54, no.4, 2015-03-27

被引用文献数

3

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In this paper, we present a rail-to-rail folded-cascode amplifier (AMP) with adaptive biasing circuits (ABCs). The circuit uses a nano ampere current reference circuit to achieve ultralow-power and ABCs to achieve high-speed operation. The ABCs are based on conventional circuits and modified to be suitable for rail-to-rail operation. The measurement results demonstrated that the AMP with the proposed ABCs can operate with an ultralow-power of 384 nA when the input voltage was 0.9 V and achieve high speeds of 0.162 V/µs at the rise time and 0.233 V/µs at the fall time when the input pulse frequency and the amplitude were 10 kHz and 1.5 V<inf>pp</inf>, respectively.

著者

Hayashi Shinji Nesterenko Dmitry Sekkat Zouheir

出版者

Institute of Physics

雑誌

Appl. Phys. Express (ISSN:18820778)

巻号頁・発行日

vol.8, no.2, 2015-01-06

被引用文献数

84

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A planar multilayer structure that allows coupling between surface plasmon polaritons and waveguide modes is proposed. Calculated reflectivity curves exhibit sharp resonances due to the Fano resonance and plasmon-induced transparency arising from the coupling. Electric field profiles obtained at the resonances demonstrate the hybrid nature of the modes excited. When the Fano resonance is used for sensing, the sensitivity with intensity modulation is enhanced by two orders of magnitude relative to that of conventional surface plasmon resonance sensors.

著者

Hoshi Takayuki Ochiai Yoichi Rekimoto Jun

出版者

Institute of Physics

雑誌

Jpn. J. Appl. Phys. (ISSN:00214922)

巻号頁・発行日

vol.53, no.7, 2014-06-12

被引用文献数

70

著者

Courdurier M Noo F Defrise M Kudo H

出版者

Institute of Physics

雑誌

Inverse problems (ISSN:02665611)

巻号頁・発行日

vol.24, no.6, pp.065001, 2008-12

被引用文献数

92 80

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A case of incomplete tomographic data for a compactly supported attenuation function is studied. When the attenuation function is a priori known in a subregion, we show that a reduced set of measurements are enough to uniquely determine the attenuation function over all the space. Furthermore, we found stability estimates showing that reconstruction can be stable near the region where the attenuation is known. These estimates also suggest that reconstruction stability collapses quickly when approaching the set of points that is viewed under less than 180°. This paper may be seen as a continuation of the work 'Truncated Hilbert transform and image reconstruction from limited tomographic data' (Defrise et al 2006 Inverse Problems 22 1037). This continuation tackles new cases of incomplete data that could be of interest in applications of computed tomography.