| 研究生: |
林俊圜 Lin, Chun-Yuan |
|---|---|
| 論文名稱: |
全息曝光製程於聚合物網絡液晶盒摻雜不同濃度的手性分子製作偏振無關相位調制器之研究 Study of polarization-independent phase modulators fabricated by holographic photo exposure in polymer network liquid crystal cells with various concentration of chiral dopant |
| 指導教授: |
許家榮
Sheu, Chia-Rong |
| 學位類別: |
碩士 Master |
| 系所名稱: |
理學院 - 光電科學與工程學系 Department of Photonics |
| 論文出版年: | 2018 |
| 畢業學年度: | 106 |
| 語文別: | 中文 |
| 論文頁數: | 66 |
| 中文關鍵詞: | 偏振無關相位調制器 、全息曝光 、聚合物網絡液晶 、手性分子 |
| 外文關鍵詞: | polarization-independent phase modulator, chiral dopant, polymer network liquid crystal, holographic exposure |
| 相關次數: | 點閱:167 下載:1 |
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本論文主要的研究內容是利用全息曝光製程於聚合物網絡液晶盒摻雜不同濃度的手性分子製作偏振無關相位調制器。在曝光製程時,液晶樣品處於高溫條件以使液晶盒內之混合物達到各向同性的狀態。
本實驗中採用的光聚合物為RM257,並摻雜不同濃度手性分子S811。相位調制器製作之曝光條件為樣品控溫於100 ℃條件下使用紅光氦氖雷射光強度2 mW/cm2進行曝光3分鐘,所製作之最佳液晶相位調制器具有於可見光波段內85 %以上的穿透率、660~710 μs的快速反應時間、外加120 Vrms下約1.1 π的偏振無關相位調制能力等特性。
本實驗亦發現當元件在較高電壓操作後,其無電壓驅動時的液晶分子排列與初始條件時的情形不一致,造成電壓調制相位的困難。為了克服此問題,實驗嘗試利用熱退火處理電壓操作後之相位調制器使其回復電壓操作前的初始狀態,並比對熱退火前後之元件特性是否一致,結果發現確實可以透過熱退火步驟使其還原初始狀態且維持住元件原本特性。
Using holographic photo exposure to process polymer network liquid crystal cells with various concentration of chiral dopant in the high temperature isotropic phase, it is available that liquid crystal micro-domains with random director orientations can be achieved in cells at room temperature. Three various concentrations of 10, 15, and 20 wt% chiral dopant were investigated for the fabrications of liquid crystal phase modulators in this study. The final optimal performance of fabricated phase modulator show capabilities including low light scattering, high transmittance over 80 % achieved in the visible wavelength spectrum, sub-millisecond optical response, polarization-independence, and 1.1π phase modulation range. However, an occurred issue must be solved that the electrically driven phase modulators cannot return to their initial cell statuses without applied voltage so that inconsistent phase modulations occurred. A proposed way of thermal annealing was used to overcome this issue and confirm the consistence of phase modulations in the fabricated devices.
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