DEVEROPEMENT OF NONLINEAR RELAXATION SPECTROMETER IN A FREQUENCY DOMAIN
| Project/Area Number |
09555020
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Applied physics, general
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HAYAKAWA Reinosuke THE UNIVERSITY OF TOKYO,GRADUATE SCHOOL OF ENGINEERING,PROFESSOR, 大学院・工学系研究科, 教授 (00011106)
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| Co-Investigator(Kenkyū-buntansha) |
FURUSAWA Hiroshi THE UNIVERSITY OF TOKYO,GRADUATE SCHOOL OF ENGINEERING,ASSISTANT, 大学院・工学系研究科, 助手 (20282684)
KIMURA Yasuyuki THE UNIVERSITY OF TOKYO,GRADUATE SCHOOL OF ENGINEERING,LECTURER, 大学院・工学系研究科, 講師 (00225070)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥11,400,000 (Direct Cost: ¥11,400,000)
Fiscal Year 1998: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1997: ¥8,900,000 (Direct Cost: ¥8,900,000)
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| Keywords | NONLINEAR RESPONSE / RELAXATION SPECTRUM / DYNAMICS / DIELECTRIC RELAXATION / ELECTROOPTIC RESPONSE / FERROELECTRIC LIQUID CRYSTALS / 誘電緩和スペクトル / 電気光学スペクトル / 周波数スペクトル / 高調波スペクトル / デジタル・バランス法 / 非線形複素誘電率 / 非線形複素導電率 |
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| Research Abstract |
As a response to external field easily becomes nonlinear in soft condensed matters such as polymers and liquid crystals, the nonlinear relaxation spectroscopy is an useful method to investigate the dynamics of these matters. We have developed the nonlinear relaxation spectrometer in a frequency domain using a sinusoidal electric field as an input. In our system, harmonic distortion of the applied electric field has been removed by low-pass filter and the nonlinear responses have been extracted from response signals after cancel of the fundamental component by the digital balancing method. The digital balancing method makes it possible to measure the nonlinear spectra with high accuracy free from the dynamic range of the spectrometer.
We have applied the developed system to ferroelectric liquid crystals in the SmC^* phase and checked the usefulness of the system. The measured linear and third-order nonlinear spectra are found to make good agreement with those calculated theoretically. We have succeeded in the evaluation of the material constants which are important in the display application such as spontaneous polarization and rotational viscosity by the comparison between those two spectra.
We have also applied that system to the nonlinear electrooptic measurement, in which the intensity of the transmitted intensity through cells filled with ferroelectric liquid crystals is detected as an output signal. It is found the odd harmonic spectra offer the similar information to that obtained from the nonlinear dielectric spectra and the even harmonic spectra offer the information on the electric and optical anisotropy of liquid crystals.
In conclusion, we have developed new nonlinear relaxation spectrometer and showed the usefulness of the system in the study of dynamics of liquid crystals.
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Report
(3 results)
Research Products
(10 results)
