本論文是利用液晶來做成Fresnel透鏡[1]，液晶透鏡是一個很未來性的研究;一般的傳統固態鏡頭組需要比較大的驅動電流以及聚焦程度不可調控等先天條件，因此我們利用液晶來作為透鏡，可以利用液晶本身的雙折射性以及可利用電壓來驅動液晶分子導軸來調制聚焦效率。因此本論文期望以新的結構做出光電場偏振方向無關以及低操作電壓的液晶透鏡。

論文中第一部分:所做的液晶樣品A為水平配向結構，因此我們可以利用不同電場偏振方向的入射光或是外加電壓的方式來調控液晶盒的折射率，來調控有無聚焦。

論文中第二部分:所做的液晶樣品B為上基板為垂直配相，下基板為同心圓的水平配向，因此我們可以利用外加電壓的方式來調控液晶盒的折射率，所以在第二部分所做的液晶透鏡是可利用不同外加電壓來調控有無聚焦而且因為同心圓配向的關係所以與入射光的偏振無關，而且每單位m之操作電壓範圍是目前與偏振無關之LC Fresnel Lens 中最佳的。

We have demonstrated two types of electrically controllable LC Fresnel lenses based on liquid crystal-polymer composite films in this thesis.

First experiment：
This experiment elucidates a Fresnel lens using a simple approach that is based on a homogeneously aligned liquid crystal (LC) film with a preformed polymer relief pattern. Experimental results demonstrate that the LC Fresnel lens has polarization-dependent and electrically switchable focusing features. The LC lens has the further advantages of a weak operated field, and high diffraction efficiency.

Second experiment：
This experiment reports a Fresnel lens in a circularly-symmetric hybrid-aligned liquid crystal (LC) film with a photoconductive polymer layer. An ultraviolet-induced electrode-like pattern of polymer layer under a zone-plate photomask results in alternate unscreened and screened effects of an applied dc-field at conductive and nonconductive regions, respectively. These effects cause a discrepancy of LC reorientation in adjacent zones and in turn generate a Fresnel lens. The focusing of the lens is demonstrated electrically-controllable and polarization-independent. Furthermore, the lens has advantages of an zero-focusing in voltage-off state and a very small operated dc-field range from 0 - 0.3 V/um.

1.J. S. Patel and K. Rastani, Opt. Lett, 16, 532 (1991)
2.Hisanao Sato, Shusuke Ono, and Eiji Ando, J. Appl. Phys., 45 1675 (1974)
3.Yi-Sheng Lai, Chia-Hsun Tu, and Dim-Lee Kwong, Appl. Phys. Lett., 87 122101 (2005)
4.J. Mort and P. Nielsen, Phys. Rev. B, 5, 8 (1972)
5.J. Jahns and S. J. Walker, Appl. Opt. 29, 931-936 (1990).
6.J. S. Patel and K. Rastani, Opt. Lett. 16, 532-534(1991).
7.Kasra Rastani, Abdellatif Marrakchi, Sarry F. Habiby, William M. Hubbard, Harold Gilchrist, and Robert E. Nahory, Appl. Opt. 30, 1347-1354 (1991).
8.Yun-Hsing Fan, Hongwen Ren, and Shin-Tson Wu, Opt. Express 11, 3080-3086 (2003).
9.Hongwen Ren, Yun-Hsing Fan, Shin-Tson Wu, Appl. Phys. Lett. 83, 1515-1517 (2003).
10.Dong-Woo Kim, Chang-Jae Yu, Hak-Rin Kim, Sung-Jin Kim, and Sin-Doo Lee, Appl. Phys. Lett. 88, 203505-1-3 (2006).
11.Tsung-Hsien Lin, Yuhua Huang, Andy Y. G. Fun, and Shin-Tson Wu, Opt. Express 14, 2359-2364 (2006).
12.Andy Ying-Guey Fuh and Ko-Ting Cheng, Jpn. J. Appl. Phys. 45, 8778–8781 (2006).
13.C.R. Lee, T. S. Mo, K. T. Cheng, T. L. Fu, and A. Y. –G. Fuh, Appl. Phys. Lett. 83, 4285-4287 (2003).
14.C.R. Lee, T. L. Fu, K. T. Cheng, T. S. Mo, and A. Y. –G. Fuh, Phys. Rev. E 69, 031704 (2004).
15.San-Yi Huang et al, Appl. Phys. Lett. 88, 041104-1-3 (2006).
16.松本正一 角田市良 合著,劉瑞祥 譯, “液晶之基礎與應用,”國立編譯館出版 (1996).
17.液晶應用技術研究會 著, “最新液晶應用技術”, 建興出版社(1997).
18.紀國鐘、鄭晃忠 主編, “液晶顯示器技術手冊”, 台灣電子材料與元件協會(2002).
19.小林駿介 著, “e世代液晶顯示器”, 全華圖書 (2002)
20.Pochi Yeh et al, “Optical of Liquid Crystal Display,” John Wiley & Sons Inc. (2006).
21.楊建人 譯, “光學原理”, 徐氏文教基金會 (2001).
22.李冠卿 著, “近代光學”, 聯經出版事業公司(1988).
23.(朱自強, 王仕璠, 蘇顯渝, 現代光學教程, 四川大學出版社, 成都(1990).)