標題: | Acoustic realigment of nematic liquid crystals by guided waves |
作者: | Lee, Yu-Ching Shih, Wun-Bin Su, Yu-Wei Yin, Ching-Chung 機械工程學系 Department of Mechanical Engineering |
關鍵字: | nematic liquid crystals;acoustic realignment;guided acoustic waves |
公開日期: | 2007 |
摘要: | This paper presents an experimental evidence to correlate the acousto-optic effect of nematic liquid crystals to modal excitations of guided acoustic waves. The optic axes of liquid crystal molecules in a cell can be tilted by ultrasound at oblique incidence. The cell filled with homeotropically aligned liquid crystal material, 5CB, is fully immersed in a water tank situated between two crossed polarizers. Multi-modal guided acoustic waves have been excited in cell by changing the angle of incidence and driving frequency. The liquid crystal material sandwiched between two glass plates is regarded as a Newtonian fluid and modeled to be an isotropic hypothetical solid. The phase velocity dispersion curves and associated modal strains within the liquid crystal cell are determined numerically. Comparison between measured data and prediction reveals that guided acoustic waves have influence on the acousto-optic response of liquid crystals rather than bulk acoustic waves. Simulated results show that homeotropically and homogeneously aligned liquid crystals can be affected by symmetric and antisymmetric modes, respectively. |
URI: | http://hdl.handle.net/11536/11878 http://dx.doi.org/10.1109/ULTSYM.2007.213 |
ISBN: | 978-1-4244-1383-6 |
ISSN: | 1051-0117 |
DOI: | 10.1109/ULTSYM.2007.213 |
期刊: | 2007 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1-6 |
起始頁: | 832 |
結束頁: | 835 |
顯示於類別: | 會議論文 |