English  |  正體中文  |  简体中文  |  Items with full text/Total items : 69937/69937 (100%)
Visitors : 23030662      Online Users : 442
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version

    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/83527

    Title: 膽固醇液晶摻雜偶氮苯材料之頻譜調制及其應用;Spectrum modulation of azobenzene-doped cholesteric liquid crystals and their applications
    Authors: 袁銘鴻;Yuan, Ming-Hong
    Contributors: 光電科學與工程學系
    Keywords: 偶氮苯手性分子;光控膽固醇液晶;頻譜拓寬
    Date: 2020-08-20
    Issue Date: 2020-09-02 15:46:20 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 本論文所使用之偶氮苯材料照射紫光可使其從反式轉變為順式結構;而照射可見光可從順式轉變回反式,此反應稱為光致異構化反應,且此反應為可逆反應,亦即可多次來回變換。偶氮苯材料之順式及反式結構通常具有不同的物理特性,因此廣泛應用於光控元件的製作。
    ;The trans-cis (cis-trans) transitions of azobenzene materials adopted in this thesis occur when they are illuminated with an ultraviolet (visible) light. Such a reversible reaction is called the photoisomerization effect. The physical properties of trans-isomers are usually different from those of cis-isomers, so azobenzenes can be widely applied to the applications of photosensitive optical devices.
    In this thesis, the mixture of nematic liquid crystals (LCs) with negative dielectric anisotropy (HNG30400-200), right-handed chiral dopant (R1011), and left-handed chiral azobenzene (ChAD-2-S) was adopted. The disparities of the adopted chiral azobenzenes between trans-isomers and cis-isomers, such as the tunable helical twisting power (HTP), play the key to shift the reflection band of the cholesteric LCs (CLCs) with the illumination of different wavelength light sources. The topics in the thesis include three parts. The first one is to study the tunable reflection bands of the CLCs by simultaneously illuminating with green and purple light onto the CLCs. With the illumination of green light having a constant intensity, the CLC reflection band will be blue-shifted. The range of shifted wavelength increases with the increase of the intensity of purple light within a specific range. We also observed that the reflection band can be broadened by proper increasing the intensities of both lights. Additionally, the shifts of the reflection bands, resulting from the simultaneous illumination of green and purple lights from the same side and the opposite sides of the CLC cell were investigated. Second, binary planar textures with two different pitch lengths, generated by illumination of light through a suitable mask, in a single CLC cell are also proposed to spatially broaden the reflection band of the CLCs. The difference between the reflection band, resulting from the illumination of a single purple light, and that obtained by the simultaneous illumination of purple and green lights, was examined. As described in the first part, the simultaneous illumination of green and purple lights from the same side and the opposite sides of the CLC cell is worth to be discussed. In the last part, the approach to obtain a light source having a narrow bandwidth was proposed. With the illumination of purple light onto the part of the CLC cell, two regions, reflecting lights with different wavelength ranges, can be obtained. A wide-band light source becomes a narrow-band one if the incident light passes through the two regions in the CLC cell twice. As a result, the undesirable component of light can be filtered out, and a narrow band unpolarized light source can be retained.
    Appears in Collections:[光電科學研究所] 博碩士論文

    Files in This Item:

    File Description SizeFormat

    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback  - 隱私權政策聲明