主鏈型高分子液晶-雙丙烯酸酯異構物，RM257、RM82為具有液晶態並具有光敏特性的材料。我們過去研究發現，以兩款非主要吸收波段雷射光源照射，竟引致聚合。藉由光穿透率與強度關係計算出雙光子吸收係數，加以非線性光學量測法，Z-scan檢驗，觀察到在相變點附近有明顯的反飽和吸收。確立雙光子吸收為引致聚合的機制。
基於此複合特性，以雙光束(S-S偏振)干涉光場照射雙丙烯酸酯異構物。並藉由週期性建設性干涉光場與破壞性干涉光場在樣品上形成相對應之一維柵狀結構。觀察此柵狀結構，可發現部分區域有一致指向。本研究中，以相位延遲法觀測其內部分子指向。此外，以實驗驗證樣品在偏光顯微鏡下觀察到的亮、暗條紋，各別對應到建設性或破壞性干涉光場。
相較於提供單一光子能量的雷射光源，長波寬譜光源(λ>550 nm)也能引致聚合但需要更久時間。亦即雷射光源相較長波寬譜光源有較高的機率引致雙光子吸收。
預配向RM82樣品在向列液晶態有較為一致的排列。以He-Ne雷射為光源、不同偏振單光束，預配向方向或平行偏振方向或垂直偏振方向，聚焦後照射預配向樣品。觀測其聚合時間、聚合後的表面形貌及分子指向。一方面可藉此比較何種影響較鉅；高分子鏈或溝槽給予之錨定能；另一方面，可觀察聚合後表面形貌是否有改變。進一步，控制此柵狀結構內部指向，有做為相位光柵、光誘發配向、光子晶體…光電元件的潛力。

Mesogenic diacrylate, RM257、RM82, kinds of main chain liquid crystal
polymers (MCLCPs) and light-sensitive materials. In our past research, two kinds of
laser light source induced the diacrylate mesogen polymerization was discovered. We
calculated the two-photo absorption coefficients by the transmission against intensity
of mesogenic diacrylate. Through none- linear optical measurement, Z-scan, the
reverse saturable absorption curve was observed near phase-transition temperature.
According to the TPA (two-photo absorption) coefficient and NLO (none-linear
absorption) effect, two-photo absorption progress to induce polymerization was
confirmed.
Base on the above characteristics, two –beam interference field with s-polarized
was applied to form a periodic grating on mesogenic diacrylate. Some stripes of the
grating oriented were observed. In this study, phase-retardation method was applied to
identify the director of the grating. In addition, experiments to make sure the
interference field; destructive field and constructive field each represent the stripes
dark or bright of grating in POM (polarizing optical microscope) observing.
As we know the polymerization time of light source of He-Ne laser (one beam)
irradiating to the RM82 cells. Compare to laser, broad-band light source(λ>550 nm)
also induced polymerization of RM82 but spending more time. That is, there is much
higher probability for laser light source than broad-band light source to cause TPA.
Pre-aligned RM82 sample oriented at nematic phase. One beam with different
polarization(p-polarized 、 s-polarized) illuminated pre-aligned sample to verify
polarization having less effect on orientation.. Through controlling the director and
polymerized area to obtain aligned cell which has potential for electro-optic device.

致謝........................................................................................................................ i
Abstract..................................................................................................................iii
目錄........................................................................................................................iv
圖目錄....................................................................................................................vii
表目錄.................................................................................................................... x
第一章 緒論............................................................................................................ 1
第二章 液晶簡介...................................................................................................... 2
2-1 液晶態 ..............................................................................................................2
2-2 液晶物理簡介 .................................................................................................... 2
2-2.1 指向向量與秩序參數 ....................................................................................... 2
2-2.2 電學異向性 .................................................................................................... 4
2-2.3 光學異向性 .................................................................................................... 5
2-2.4 連續彈性體理論 ...............................................................................................7
2-2.5 向列液晶態分子配向理論簡介 ...........................................................................8
第三章 高分子液晶................................................................................................. 11
3-1 高分子液晶簡介 ............................................................................................... 11
3-1.1 背景 ............................................................................................................ 11
3-1.2 分類 ................................................................................................... .........12
3-2 聚合 (Polymerization) .......................................................................................13
3-2.1 聚合過程簡介 ................................................................................................13
3-2.2 聚合反應分類 ................................................................................................13
第四章 雙丙烯酸酯的雙光子吸收現象........................................................................16
4-1 背景簡介 .........................................................................................................16
4-2 原理 ................................................................................................................16
4-3 雙光子吸收截面檢測法 ......................................................................................18
4-3.1 非線性穿透率法 .............................................................................................18
4-3.2 Z-scan 法 ......................................................................................................20
4-3.3 雙丙烯酸酯異構物於雙光子吸收檢測法的結果討論 ........................................... 22
第五章 光場作用下雙丙烯酸酯的聚合現象.................................................................23
5-1 樣品製備 .........................................................................................................23
5-2 樣品指向判別 ...................................................................................................25
5-2.1 實驗架設 .......................................................................................................25
5-2.2 雙丙烯酸酯材料介紹 ......................................................................................28
5-2.3 樣品聚合後外觀與光學圖像分析 ......................................................................29
5-2.4 液晶分子指向辨別法 ......................................................................................30
5-2.5 相位延遲法檢驗指向 ......................................................................................33
5-2.6 指向檢驗結果 ................................................................................................40
5-3 條紋區域相對於干涉光場區域判別 ......................................................................40
5-3.1 實驗架設 .......................................................................................................41
5-3.2 P 偏振單光束通過鋁箔光罩照射樣品結果 .........................................................41
5-3.3 P-P 偏振雙光束干涉光場照射樣品結果 ............................................................43
5-4 檢驗長波段寬譜光源對 RM82 樣品聚合的影響 .....................................................44
5-4.1 鹵素燈光譜(J-150W, 78 mm) ..........................................................................44
5-4.2 實驗架設 .......................................................................................................44
5-4.3 結果 .............................................................................................................45
5-5 光場偏振與表面作用力於 RM82 的影響 ..............................................................48
5-5.1 預配向 RM82 樣品 .........................................................................................48
5-5.2 改變偏振照射預配向 RM82 樣品 .....................................................................48
5-5.3 結果 .............................................................................................................49
第六章 總結............................................................................................................50
6-1 樣品指向判別與相對應光場辨識 .........................................................................50
6-2 檢驗長波寬譜光源對 RM82 樣品聚合的影響 ........................................................51
6-3 光場偏振與表面作用力於 RM82 的影響 ..............................................................52
參考文獻............................................................................................................... 53

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