臺灣博碩士論文加值系統

表面電漿共振(surface plasmon resonance, SPR)對表面結構、金屬厚度或介質層折射率等的變化非常敏感。
液晶具有各方異向性，在光學上光線所感受到的折射率與光前進方向、光場偏振有關。
本實驗將具有雙折射性之單光軸晶體結構向列型液晶(nematic liquid crystal，NLC)E7注入具有金屬光柵之液晶盒，並將其置於稜鏡之上(Kretschmann結構)，藉由液晶電光調制之特性當作耦合出表面電漿波的開關，希望藉由改變液晶折射率，使得pumping光源耦合或者不耦合來達成液晶調控表面電漿共振模態現象。

Surface plasmon resonance (SPR) is sensitive to surface structure, metal thickness or refraction index of medium layer.
Liquid crystal is anisotropic, and optically, the refraction index of light is related to its direction and polarization.
In this research, the birefringent nematic liquid crystal (NLC) with uniaxial crystal structure, E7, was injected to a liquid crystal cell with metallic gratings, and placed on a prism with Kretschmann structure. From the characteristics of electro-optical modulation of liquid crystal, E7 was used to serve as the switch which can couple surface plasma wave. Pumping light source was controlled to be coupled or un-coupled by changing the refraction index of liquid crystal, and SPR mode effect modulated by liquid metal would be reached.

致謝 i
摘要 . ii
Abstract iii
目錄 iv
圖次 vi
表次 . viii
1 第一章 序論 . 1
1.1 前言 1
1.2 文獻回顧與研究目的 1
1.3 論文架構 . 2
2 第二章 表面電漿波 . 3
2.1 全反射與衰逝波 . 4
2.2 金屬的光學性質 . 5
2.3 金屬平面之表面電漿波模態 9
2.4 表面電漿共振激發架構 12
2.4.1 光柵耦合(grating coupler) . 12
2.4.2 稜鏡耦合(prism coupler) 13
2.5 三層結構反射率之理論 14
3 第三章 液晶 18
3.1 液晶簡介 18
3.2 液晶分類 18
3.3 液晶的物理特性 20
3.3.1 秩序參數 . 20
3.3.2 折射率異向性 20
3.3.3 介電異向性 23
3.4 光於單光軸晶體之特徵電場 24
3.5 光軸在YZ 平面三層結構下之表面電漿波[10] 25
4 第四章 實驗方法與步驟 30
4.1 樣品製備 30
4.1.1 奈米金屬光柵基板之製備 30
4.1.2 液晶盒之製備 33
4.2 量測架構與方法 35
5 第五章 結果與討論 36
5.1 金屬光柵置於稜鏡上之波向量水平分量 . 36
5.2 液晶調控黃金光柵表面電漿模態之分析 . 39
5.2.1 金膜厚度40nm 之一維光柵 39
5.2.2 金膜厚度100nm 之一維光柵 . 45
5.2.3 金膜厚度50nm 之二維光柵 46
6 第六章 結論 48
7 參考文獻 . 49

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