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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/2314

    Title: 具高分子電光調變器之調頻分頻多工影像傳輸系統;FM-FDM Optical Video Transmission Using a E-O Polymer Light Modulator
    Authors: 施至鴻;Chih-Hung Shih
    Contributors: 機械工程研究所
    Keywords: 調頻;影像傳輸;分頻多工;電光調變器;video transmission;FDM;light modulator;FM
    Date: 2003-06-24
    Issue Date: 2009-09-21 11:43:33 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 在今日講求高品質的多媒體傳輸系統下,分頻多工系統(frequency- division-multiplexing,FDM)一直在通訊系統中佔有相當的地位,而使用調頻(frequency modulation,FM)方式於類比影像傳輸系統,訊號在傳輸的過程中,能獲得較好的訊雜比、失真度低及受環境影響因素低,也較數位傳輸方式較為經濟。 在本文中將呈現利用自製高分子電光調變器於高頻雷射調變及解調電路,完成調頻分頻多工影像傳輸系統。調頻解調電路,分別使用電壓控制振盪器(voltage-controlled oscillator,VCO)與相位栓鎖迴路(phase locked loop,PLL)來完成,電壓控制振盪器有良好的輸入電壓與輸出頻率關係,能給予極佳的線性度,使用相位栓鎖迴路解調,由於不受輸入訊號的振幅影響,能獲得較佳的解調輸出,且在電路積體化之後使用更為便利。 而高分子電光調變器於高頻雷射調變上,其特色為一種工作電壓小且動態特性佳的光調變器—利用電場改變入射光波與波導耦合模態表面電漿共振(waveguide-coupled surface plasmon resonance,WCSPR)之間的耦合程度,其中有機電光高分子材料因外加電場形成一階電光效應,造成其折射率發生變化,進而使反射光的強度產生線性變化而達到光調變的目的。 Because the people desire to have high quality multimedia communication, frequency division multiplexer (FDM) is always playing an important role in the communication system. By using frequency modulation (FM) for analog video communication system, it would achieve higher signal-to-noise ratio (SNR) and less susceptibility to nonlinear distortion during transmission than by using the amplitude modulation (AM). Besides, analog communication devices like FM transmitters and receivers are much cheaper than the digital communication equipments. In this thesis, we demonstrate FM/FDM analog video communication system using in-house electro-optic polymer light modulator as light transmitter. We here also used voltage-controlled oscillator (VCO) to modulate signals because of its superior linearity between input voltage and output frequency. Therefore it would produce more accurate desired frequency by controlling input voltage. Moreover we choose phase locked loop (PLL) circuit as our demodulator circuit because PLL has wider deviation range and less sensitivity to noise as compared to other discriminators The electro-optic polymer light modulator has some characterizations such as low driving voltage and large aperture. By combining Pockels effect from electro-optic polymer material and waveguide coupled of surface plasmon resonance, it is demonstrated that this kind of modulator operated with less applying modulation voltage, less optical insertion loss and easy alignment as compared to other light modulation techniques.
    Appears in Collections:[機械工程研究所] 博碩士論文

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