臺灣博碩士論文加值系統

在本論文中我們主要所探討的，是染料分子(Methyl Red)摻雜在液晶(E7)薄膜中，受光激發所產生的現象。這個現象大致上來說可以由兩個部分組成，一個是染料分子的吸附效應(adsorption)，另一個則是吸附染料由雷射導致所形成波紋(ripple)的溝槽，這兩個效應與入射光(Ar+雷射514.5nm)的偏振、光強、及照光時間有絕對的相關。在而不同的條件下，染料分子的吸附及引致波紋結構的溝槽，對液晶分子的配向，有著迥異的效果。本實驗主要分10mW的強光和0.1mW的弱光來討論，而樣品製作是利用液晶盒，其單面做水平配向處理，雷射光由未經處理的ITO玻璃基板(test side)入射，吸附在test side上的染料分子給予這面上的液晶一個易軸，與水平配向的rubbing方向在樣品中形成一個扭轉配向(TN)，透過偏振光學顯微鏡及一些簡單的光學實驗，我們可以推知吸附效應及ripple溝槽相對光強、時間的關係，藉著SEM、AFM的照片，可以更加驗證實驗所得之結論。

The main topic discussed in this thesis is the laser-induced effect in the dye-doped liquid crystal films. The phenomenon, in general, is caused by the dye molecule adsorption effect and the laser-induced ripple structure. These two effects are directly related to the polarization and the intensity of the laser (Ar+ laser at 514.5 nm), and the length of the exposure time. Under different conditions, the dye molecule adsorption and the groove (pattern) of the ripple structure distinctively. The lasers selected for this experiment are mainly 10 mW high intensity and 0.1mW low intensity lasers. The sample is prepared using a cell with one substrate treated homogeneous alignment. The other is not treated. Laser light enters (the sample) from the non-treared ITO glass substrate test side. The dye molecules adsorbed on the test side induce the twist structure in the liquid crystal along the easy axis and the homogeneous (rubbing) direction. Through the polarization microscope and a few simple experiment, we can deduce the adsorption effect and the ripple groove (pattern) at different laser intensity and time. The images obtained from SEM and AFM further confirm our experimental results.

第一章 簡介
1-1前言…………………………………………………………………1
1-2何謂液晶……………………………………………………………1
1-3液晶分類……………………………………………………………2
1-4液晶特性……………………………………………………………10
1-4.1 光學特性……………………………………………………………11
1-4.2 介電性質……………………………………………………………14
1-4.3 形變理論……………………………………………………………18
第二章 理論
2-1 摻雜染料之液晶薄膜………………………………………………19
2-2 雷射引致光柵………………………………………………………20
2-2.1 同調雷射相干之週期性變化場……………………………………20
2-2.2 光柵分類……………………………………………………………25
2-2.3 光柵機制……………………………………………………………28
2-3 液晶摻雜染料分子效應……………………………………………29
2-3.1 染料分子受光激發後的效應………………………………………29
2-3.2 吸附效應引致液晶排列……………………………………………34
2-3.3 雷射引致波紋(Ripple)……………………………………………34
2-4 扭轉配向……………………………………………………………36
第三章 實驗備置
3-1 材料介紹……………………………………………………………37
3-2 樣品製作……………………………………………………………39
3-3 實驗裝置架構………………………………………………………45
3-4 實驗器材介紹………………………………………………………48
第四章 實驗結果與討論
4-1 實驗動機……………………………………………………………52
4-2 實驗歷程……………………………………………………………52
4-3 實驗結果……………………………………………………………57
4-3.1 定性推導光強、時間差異下所形成的不同吸附…………………57
4-3.2 以光學方法驗證染料分子吸附的機制……………………………71
4-4 雷射引致光柵………………………………………………………105
第五章 結論
5-1 結論…………………………………………………………………112
5-2 未來工作……………………………………………………………113
參考文獻………………………………………………………………………116

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