簡易檢索 / 詳目顯示

回結果列表
研究生： 鄭恪亭
Cheng, Ko-Ting
論文名稱： 偶氮染料摻雜液晶薄膜之雙光子效應研究及其應用
Studies of Biphotonic Effect in Azo-Dye-Doped Liquid Crystal Films and Their Applications
指導教授： 傅永貴
Fuh, Ying-Guey Andy
學位類別： 博士
Doctor
系所名稱： 理學院 - 物理學系
Department of Physics
論文出版年： 2007
畢業學年度： 95
語文別： 英文
論文頁數： 125
中文關鍵詞： 液晶 、偶氮染料 、雙光子效應
外文關鍵詞： biphotonic effect, liquid crystals, azo dyes
相關次數： 點閱：77  下載：8 
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

    • 近幾年來，偶氮衍生物(如偶氮苯、偶氮染料等)由於其奇特的異向特性已受到科學家們的重視與研究，並且將其應用在液晶元件的配向技術上。在這之中，在偶氮染料摻雜液晶薄膜中，利用單一激發光使偶氮染料吸附於基板上的應用在這幾年來亦受到極度的重視，這種效應即稱為單光子效應。在單光子效應於本系統的應用中，許多光學元件，如顯示器、全像光柵、透鏡、濾波片、偏振片等已被研究發展出來。在這個光配向技術中最主要的機制莫過於光引致染料分子吸附效應，總括來說這個效應起因於以下幾個效應：正/負力矩效應、光致同素異構化效應、吸附/脫附效應。本論文將提出在偶氮染料摻雜液晶薄膜中由兩種不同光子所產生的雙光子效應(一道紅光及一道綠光)。本論文的目標在研究於偶氮染料摻雜液晶薄膜中所發生的有趣之物理現象，如電、熱、光、化學等效應。簡而言之，本論文包含著兩個有關雙光子效應的研究主題，其一為偶氮染料摻雜液晶薄膜中之液晶光配向的應用、另一為偶氮染料摻雜液晶薄膜中之雙光子全像光柵的製作及動態研究。

    本論文的第一部份是研究於偶氮染料摻雜液晶薄膜中雙光子光配向之技術，我們利用掃瞄式電子顯微鏡及原子力顯微鏡觀察並提出了雙光子雷射引致波紋結構，該結構是由紅光及綠光於吸附表面所散射的光及其入射光所分別形成之干涉場互相反應而形成，並證明足以配向液晶分子。我們也發現紅光及綠光的強度比、偏振方向、光波長及外界溫度皆影響該波紋的形成及結構。此外，由另一部份的實驗，我們提出了雙光子效應可應用於抹除吸附於基板上的偶氮染料，其中紅綠光強度比及相對之偏振方向皆會影響雙光子抹除技術的效率。

    第二部分的研究是有關於雙光子全像光柵的形成及其動態之研究，我們成功地研究出可電壓開關及熱抹除的雙光子偏振光柵。此外，我們也研究了在偶氮染料摻雜液晶薄膜中雙光子強度光柵之光及熱效應的動態過程，該部分的實驗我們提出了雙光光柵的機制包含兩個重要的效應，分別為基板內部分子轉向效應及表面吸附效應。

    Azo derivatives, such as azobenzene, azo dyes ..., etc. have been studied intensively in recent decades. Many researchers use such materials to develop the photo-alignment techniques in liquid crystal devices because of their particular anisotropic optical properties. Among these, the applications of azo dye adsorption in a dye-doped liquid crystal (DDLC) film induced using a single pump beam, the so-called one-photonic effect, have attracted substantial attention over the past years. Many optical devices, including displays, holographic grating, optical lens, optical filter, polarizer and so forth, have been developed in this system. The mainly mechanism in this photo-alignment of liquid crystals is the light-induced dye adsorption, which conclusively results from the positive/negative torque effect, photoisomerization effect, adsorption/desorption. In this thesis, we study the biphotonic effect, which is caused by pumping two photons of different wavelengths (one red and one green light) in a DDLC film. The aims of the thesis work are to study the related interesting physics, such as electrical, thermal, optical and chemical effects occurred in the system. Briefly, the thesis mainly consists of two topics; one is the applications of photoalignment in LCs, and the other is the fabrications of controllable holographic polarization/intensity gratings using biphotonic technique based on azo dye-doped liquid crystal films are the in this thesis.

    In the first part, we propose a biphotonic laser-induced ripple structures (BLIRSs), analyzed using scanning electron microscopy and atomic force microscopy to alignment LCs. A BLIRS is formed by competing red and green light interfering fields, generated by the interference of incident red and green light with the corresponding surface scattering lights. We also investigate that the ratio of the intensity of red light to that of green light, the wavelength and polarization of the lights and the ambient temperature markedly affect the formation of the BLIRS. Moreover, a biphotonic erasure method to erase partially the photoalignment layer on an indium-tin-oxide (ITO)-coated glass slide resulted from the adsorbed azo dyes doped in a liquid crystal film. The experimental results also indicate that the intensity ratio and relative polarization should affect the efficiency of biphotonic erasure technique.

    The second part is the study of the formation and the dynamic of biphotonic gratings (BGs) in DDLC films. We successfully generate a biphotonic polarization grating, which is electrically switchable and thermally erasable. Additionally, the dynamics of biphotonic intensity holographic gratings (BIHGs) are studied. The results clearly indicate that the grating consists of two contributions; one is the bulk-reorientation effect, and the other is the surface-adsorption effect.

    摘要.............................................................................................I Abstract......................................................................................III Acknowledgement......................................................................V Contents.....................................................................................VI List of Figures.............................................................................IX List of Tables.............................................................................XV Chapter 1 Introduction 1.1 Preface....................................................................................1 1.2 Liquid Crystals........................................................................4 1.2.1 Category of Liquid Crystals.................................................5 1.2.2 Physics of Liquid Crystals..................................................12 Chapter 2 Theory 2.1 Light-Induced Molecular Reorientation Effect.......................23 2.1.1 Positive Torque Effect – Janossy Model...........................23 2.1.2 Negative Torque Effect – Gibbons Model........................25 2.1.3 Photoisomerization Effect...................................................26 2.1.4 Adsorption/Desorption Effect.............................................27 2.1.5 Light-Induced Thermal Effect............................................29 2.2 Dye-Doped Liquid Crystal Films...........................................29 2.3 Twisted Nematic Liquid Crystal Cell......................................31 2.4 Holographic Grating..............................................................34 2.4.1 Holography.........................................................................34 2.4.2 Wavefront Recording and Reconstruction...........................37 2.4.3 Laser-Induced Holographic Grating....................................40 2.4.4 Category of Gratings...........................................................47 2.5 Diffraction Theory in Thin Transmission Gratings.................50 2.6 Biphotonic Effect...................................................................56 2.7 Groove Theory.......................................................................57 2.7.1 Berreman Theory................................................................57 2.7.2 Laser-Induced Periodic Surface Structure...........................58 Chapter 3 Experimental Preparations 3.1 Related Materials...................................................................60 3.1.1 Liquid Crystals – E7.........................................................60 3.1.2 Azo Dye – Methyl Red (MR)...........................................62 3.2 Fabrication of DDLC Sample................................................64 3.3 Inspection of DDLC Sample.................................................67 3.3.1 Polarized Optical Microscope............................................68 3.3.2 Conoscopic Technology....................................................69 Chapter 4 Study of biphotonic photoalignment effect in dye-doped liquid crystal films 4.1 Biphotonic laser-induced ripple structures in dye-doped liquid crystal films 4.1.1 Introduction.......................................................................72 4.1.2 Experiments.......................................................................75 4.1.3 Results and Discussion.......................................................75 4.2 Partially erasable photoalignment layer formed in dye-doped liquid crystal films 4.2.1 Introduction........................................................................82 4.2.2 Experiments........................................................................83 4.2.3 Results and Discussion........................................................85 Chapter 5 Study of biphotonic gratings and their dynamics based on dye-doped liquid crystal films 5.1 Biphotonic recording effect of polarization gratings based on dye-doped liquid crystal films 5.1.1 Introduction.........................................................................94 5.1.2 Experiments.........................................................................95 5.1.3 Results and Discussion........................................................96 5.2 Dynamics of biphotonic holographic gratings based on dye-doped liquid crystal films 5.2.1 Introduction.......................................................................104 5.2.2 Experiments.......................................................................106 5.2.3 Results and Discussion.......................................................106 Chapter 6 Conclusions and Prospections 6.1 Conclusions...........................................................................115 6.2 Prospections...........................................................................117 References....................................................................................119 List of Publications.......................................................................124

    [1] G. P. Crawford and S. ?umer, “Liquid Crystals in Complex Geometries”, Taylor & Francis, London, 1996.
    [2] P. S. Drzaic, “Liquid Crystal Dispersions”, World Scientific Publishing, Singapore, 1995.
    [3] A. Yariv, “Optical Electronics in Modern Communications”, 5th Ed., Oxford University Press, New York, 1997.
    [4] M. HARA, S. ICHIKAWA, H. TAKEZOE and A. FUKUDA, Jpn. J. Appl. Phys., 23, 1420 (1984).
    [5] M. HARA, H. TAKEZOE and A. FUKUDA, Jpn. J. Appl. Phys., 25, 1756 (1986).
    [6] I. Janossy, A.D. Lloyd and B. S. Wherrett, Mol. Crys. & Liq. Cryst., 179, 1 (1990).
    [7] I. Janossy, L. Csillag and A.D. Lloyd, Phys. Rev. A, 44, 8410 (1991).
    [8] W. M. Gibbons, P. J. Shannon, S. T. Sun and B. J. Swetlin, Nature, 351, 49 (1991).
    [9] I. Janossy and T. Kosa, Opt. Lett., 17, 1183 (1992).
    [10] Alan G. -S. Chen and David J. Brady, Opt. Lett., 17, 1231 (1992).
    [11] A. G. Chen and D. J. Brady, Opt. Lett., 17, 441 (1992).
    [12] I. C. Khoo, Hong Li and Yu Liang, Opt. Lett., 19, 1723 (1994).
    [13] P. G. de Gennes and J. Prost, “The Physics of Liquid Crystals”, 2nd ed., Clarendon Press, Oxford (1993).
    [14] Heuberger G. and Sillescu H. J., J. Phys. Chem., 100, 15255 (1996).
    [15] T. V. Gastyan, V. Drnoyan and S.M. Arakelian, Phys. Lett. A, 217, 52 (1996).
    [16] T. V. Galstyan, B. Saad and M. M. Denariez-Roberge, J. Chem. Phys, 107, 9319 (1997).
    [17] E. Ouskova, Yu. Reznikov, S. V. Shiyanovskii, L. Su, J.L. West, O.V. Kuksenok, O. Francescangeli and F. Simoni, Phys. Rev. E, 64, 051709 (2001).
    [18] C. Sanchez, R. Cases, R. Alcala, A. Lopez, M. Quintanilla, L. Oriol and M. Millaruelo, J. App. Phys., 89, 10, 5299 (2001).
    [19] D. Voloschenko, A. Khizhnyak, Yu. Reznikov and V. Reshetnyak, Jpn. J. Appl. Phys. 34, 566 (1995).
    [20] F. Simoni and O. Francescangeli, J. Phys.: Condens. Matter 11, R439 (1999).
    [21] S. Slussarenko, O. Francescangeli and F. Simoni, Appl. Phys. Lett. 71, 3613 (1997).
    [22] Andy Y.-G. Fuh, C.-C. Liao, K.-C. Hsu, C.-L. Lu and C. -T. Tsai, Opt. Lett. 26, 1767 (2001).
    [23] A. Y.-G. Fuh, C.-R. Lee and T.-S. Mo, J. Opt. Soc. Am. B 19, 2590 (2002).
    [24] A. Y.-G. Fuh, C.-C. Liao, K.-C. Hsu and C.-L. Lu, Opt. Lett. 28, 1179 (2003).
    [25] P. Wu, B. Zou, X. Wu, J. Xu, X. Gong, G. Zhang, G. Tang and W. Chen, Appl. Phys. Lett. 70, 1224 (1997).
    [26] P. Wu, X. Wu, L. Wang, J. Xu, B. Zou, X. Gong and W. Huang, Appl. Phys. Lett. 72, 418 (1998).
    [27] P. Wu, L. Wang, J. Xu, B. Zou, X. Gong, G. Zhang, G. Tang, W. Chen and W. Huang, Phys. Rev. B 57, 3874 (1998).
    [28] C. Sanchez, R. Alcala, S. Hvilsted and P. S. Ramanujam, Appl. Phys. Lett. 77, No.10, 1440 (2000).
    [29] C. Sanchez, R. Alcala, S. Hvilsted and P. S. Ramanujam, Appl. Phys. Lett. 78, No.25, 3944 (2001).
    [30] C. Sanchez, R. Cases, R. Alcala, A. Lopez, M. Quintanilla, L. Oriol and M. Millaruelo, J. Appl. Phys. 89, 5299 (2001).
    [31] C.-R. Lee, T.-S. Mo, K.-T. Cheng, T.-L. Fu and A. Y.-G. Fuh, Appl. Phys. Lett. 83, 4285 (2003).
    [32] P. G. de Gennes and J. Prost, “The Physics of Liquid Crystals”, Oxford University Press, New York, 1993.
    [33] E. B. Priestley, P. J. Wojtowicz and P. Sheng, “Introduction to Liquid Crystals”, Princeton, New Jersey, 1975.
    [34] B. Bahadur, “Liquid Crystal- Applications and Uses, Vol.1”, World Scientific Publishing, Singapore, 1990.
    [35] I. C. Khoo and S. T. Wu, “Optics and Nonlinear Optics of Liquid Crystals”, World Scientific Publishing, Singapore, 1993.
    [36] I. Janossy and A.D. Lloyd, Mol. Cryst. Liq. Cryst. 203, 74 (1991).
    [37] I. Janossy, Phys. Rev. E, 49, 2957 (1994).
    [38] Dennis Gabor, Nature, 161, 777 (1948).
    [39] W. Y. Y. Wong, T. M. Wong and H. Hiraoka, Appl. Phys. A 65, 519 (1997).
    [40] D. Fedorenko, E. Ouskova, V. Reshetnyak and Y. Reznikov, Phys. Rev. E, 64, 031701 (2006).
    [41] P. Yeh and C. Gu, “Optics of Liquid Crystal Displays”, John Wiley & Sons, Inc., London, 1998.
    [42] P. J. Collings and M. Hird, “Introduction to Liquid Crystals”, Taylor & Francis, London, 1997.
    [43] E. Hecht, “Optics”, Addison Wesley, Berlin, 1998.
    [44] P. K. Rastogi, “Holographic Interferometry”, 3rd Ed., Springer-Verlag, Berlin, 1985.
    [45] P. Hariharan, “Optical Holography—Principles, Techniques and Applications”, Cambridge University Press, Cambridge, 1984.
    [46] P. C. Mehta and V. V. Rampal, “Lasers and Holography”, World Scientific, Singapore, 1993.
    [47] H. J. Eichler, P. G?nter and D. W. Pohl, “Laser-Induced Dynamic Gratings”, Pringer-Verlag, Berlin, 1985.
    [48] P. Yeh, “Introduction of Photorefractive Nonlinear Optics”, John Wiley & Sons, New York, 1993.
    [49] N. K. Viswanathan, S. Balasubramanian, L. Li, S. K. Tripathy and J. Kumar, Jpn. J. Appl. Phys. 38, 5928 (1999).
    [50] L. Nikolova and T. Todorov, Opt. Acta., 31, 579 (1984).
    [51] Berreman D W, Phys. Rev. Lett. 28, 1683 (1972).
    [52] R. W. Wood, Philos. Mag. 4, 396 (1902).
    [53] A. Y.-G. Fuh, M.-S. Tsai, C.-Y. Huang, T.-C. Ko and L.-C. Chien, Opt. Quantum Electron. 28, 1535 (1996).
    [54] C.-R. Lee, T.-L. Fuh, K.-T. Cheng, T.-S. Mo and A. Y.-G. Fuh, Phys. Rev. E 69, 031704 (2004).
    [55] M. Birnbaum, J. Appl. Phys. 36, 3688 (1965).
    [56] D. C. Emmony, R. P. Howson and L. J. Willis, Appl. Phys. Lett. 23, 598 (1973).
    [57] P. A. Temple and M. J. Soileau, IEEE J. Quantum Electron. 17, 2067 (1981).
    [58] F. Keilmann and Y. H. Bai, Appl. Phys. A 29, 9 (1982).
    [59] H. Niino, A. Yabe and S. Nagano, Appl. Phys. Lett. 54, 2159 (1989).
    [60] M. Bolle and S. Lazare, J. Appl. Phys. 73, 3516 (1993).
    [61] H. Hiraoka and H. Sendova, Appl. Phys. Lett. 64, 563 (1994).
    [62] Q.-H. Lu, Z.-G. Wang, J. Yin, Z.-K. Zhu and H. Hiraoka, Appl. Phys. Lett. 76, 1237 (2000).
    [63] Q.-H. Lu, X.-M. Lu, J. Yin, Z.-K. Zhu, Z.-G. Wang and H. Hiraoka, Jpn. J. Appl. Phys. 41, 4635 (2002).
    [64] A. Y.-G. Fuh, C.-C. Liao, K.-C. Hsu, C.-L. Lu and T.-S. Mo, J. Non. Opt. Phys. & Mater. 11, 57 (2002).
    [65] J. E. Sipe, J. E. Young, J. S. Preston and H. M. Van Driel, Phys. Rev. B 27, 1141 (1983).
    [66] K. Ichimura, Chem. Rev. 100, 1847 (2000).
    [67] E. Ouskova, Yu. Reznikov, S.V. Shiyanovskii, L. Su, J.L. West, O.V. Kuksenok, O. Francescangeli and F. Simoni, Phys. Rev. E. 63, 021701 (2001).
    [68] C. Z. van Doorn, J. Appl. Phys. 46, No.9, 3738 (1975).
    [69] Dwight W. Berreman, J. Appl. Phys. Lett. 46, No.9, 3746 (1975).
    [70] A. Y.-G. Fuh, C.-Y. Lu, T.-S. Mo and M.-S. Tsai, Jpn. J. Appl. Phys. 42, 7344 (2003).
    [71] H. Fei, Z. Wei, P. Wu, L. Han, Y. Zhao and Y. Che, Opt. Lett. 19, 411 (1994).
    [72] D. Statman and I. Janossy, J. Chem. Phys. 118, 3222 (2003).
    [73] T. Ya. Marusii, Yu. A. Reznikov and S. Slussarenko, Proc. SPIE Int. Soc. Opt. Eng. 2795, 100 (1996).
    [74] H.-K. Lee, K. Doi, H. Harada, O. Tsutsumi, A. Kanazawa, T. Shiono, T. Ikeda, J. Phys. Chem. B. 104, 7023 (2000).
    [75] W. Urbach, H. Hervet and F. Rondelez, J. Chem. Phys. 83, 1877 (1985).
    [76] P. Rochon, J. Gosselin, A. Natansohn, and S. Xie, Appl. Phys. Lett. 60, 4 (1992).
    [77] D. W. Berreman, J. Chem. Phys. 62, 776 (1975).
    [78] S.-Y. Huang, S.-T. Wu and Andy Y.-G. Fuh, Appl. Phys. Lett. 88, 041104 (2006).
    [79] Andy Ying-Guey Fuh, Chia-Rong Lee and Ko-Ting Cheng, Jpn. J. Appl. Phys. 42, 4406 (2003).
    [80] F. Simoni, O. Francescangeli, Y. Reznikov and S. Slussarenko, Opt. Lett. 22, 549 (1997).
    [81] O. Francescangeli, S. Slussarenko and F. Simoni, Phys. Rev. Lett. 82, 1855 (1999).
    [82] G. H. Heilmeier and L. A. Zanoni, Appl. Phys. Lett. 13, 91 (1968).
    [83] S. Chandrasekhar, “Liquid Crystals”, Cambridge University Press, Cambridge, 1992.
    [84] M. Schadt and W. Helfrich, Appl. Phys. Lett. 18, 127 (1971).
    [85] Shin-Tson Wu and Deng-Ke Yang, “Reflective Liquid Crystal Displays”, John Wiley & Sons, Inc. Ltd., Chichester, 2001.

    下載圖示 校內：2007-09-28公開
    校外：2007-09-28公開
    QR CODE