Studies of characteristics of frequency modulation liquid-crystal optoelectronic devices
| Autor: | Zheng-hsiung Chen, 陳政雄 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 We study the characteristics of the dual frequency liquid-crystal (LC) optoelectronic devices in this literary. We fabricate the LC lens with the dual frequency liquid crystal in our experiment. In this study, we first prepare a parabolic polymer structure on the glass substrate to form a polymeric lens glass, then, fill the dual-frequency LC into the empty cell which consists of one ITO glass and the polymeric lens glass to fabricate a frequency modulation LC lens. Additionally, a hybrid surface alignment is also used for our LC lens. For the dual-frequency LC, a hybrid surface alignment is necessary to obtain a frequency modulation LC lens. Because of the polymeric lens, the electric fields are inhomogeneous distributions in the LC lens when a voltage is applied to the electrodes. In this situation, an inhomogeneous electric field is applied to the cell to create GRIN lens-like distribution of the gradient refractive index. Thus, the focusing effects occur when the light passes through the LC lens. Moreover, by changing the amplitude and frequency of the applied voltage, the focal length of the LC lens can be changed. We mainly discuss the optical property and the response time of the LC lens based on the voltage modulation and the frequency modulation. The experimental results reveal that the frequency modulation has more advantages, such as widen range of controlled focal length and faster response time, comparing with the voltage modulation. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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