蔡定平臺灣大學：物理研究所黃鴻基Huang, Hung-JiHung-JiHuang2007-11-262018-06-282007-11-262018-06-282007http://ntur.lib.ntu.edu.tw//handle/246246/54661外加入射光與奈米金棒間的交互震盪可以驅動金屬表面的自由電子作群集震盪，此即為表面電漿震盪（Surface plasmon resonance, SPR）。表面電漿波導可以將光能量侷限在金屬上之週期性奈米結構、奈米金屬顆粒點串或奈米金屬棒之奈米光學系統中，而許多研究者因此將其心力集中奈米金棒的光學性質研究上。消散光譜儀（Optical extinction spectroscopy），掃針式近場光學顯微術（scanning near-field optical microscopy，SNOM），以及由乙甲基藍（methylene blue）所產生的遠場拉曼散射影像（ far-field Raman scattering ）被使用在研究與觀察奈米金屬棒之光學表現上。由於奈米金棒可作為表面電漿積體光學元件的建構基石，了解其個別光學性質，特別是入射光與其所引起表面電漿反應間的關係非常重要。 在本論文中採用了簡單的偏振對比顯微術，獲得單一奈米金棒之遠場光學影像，以避免近場光學系統中探針對奈米金棒上表面電漿模態的影響。外加光與其所誘發的表面電漿干涉，可獲得調制的駐波影像。計算影像中臨近亮點間距，可據此逆向計算其表面電漿縱波模態之波向量，並獲得了入射光波向量與其所誘發表面電漿震盪縱波膜態間之線性關係。本論文研究結果驗證了一個可行的方法，可以計算單一奈米金棒之表面電漿光學性質，與其他研究者用「不同尺寸金棒獲得的統計平均結果」方法不同，更可引申用在量測單一奈米金棒或是其他光學元件之個別光學性質上。 二氧化鈦鍍膜之光觸媒光纖（TiO2 thin film coated optical fiber, 以下簡稱「二氧化鈦光觸媒光纖」）是一個非常好的光能量傳導媒介，可以將激發光之能量傳送至遠端之光觸媒薄膜上，對於了解其光學性質對於提昇光觸媒之反應效率非常重要。在本論文中，將使用光束行進法（Beam propagation method, BPM），計算二氧化鈦光觸媒光纖的光能量傳遞指數衰減率，並計算使用紫外光發光二極體（UV-LED）為光源時，不同二氧化鈦薄膜膜厚與光能量傳遞指數衰減率之關係，以獲得最佳工作效率時之二氧化鈦膜厚。 此外，在比較純二氧化鈦及含銅（2 wt%）二氧化鈦鍍膜厚度與光能量傳遞指數之關係後，可以了解含銅金屬之二氧化鈦膜層在使用效能上將大大提昇。細究其原因，除了銅可以改變二氧化鈦的能階結構而形成可見光光觸媒外，亦應考慮銅對二氧化鈦金屬性質提昇而產生的表面電漿震盪所造成之影響。The interaction of light with nano-sized metallic structures results to driving oscillations of collective free electrons on the surface of the metal, called surface plasmon resonance (SPR). Waveguides based on SPR can provide strong guidance of light via periodic metallic structures, metallic particle chains or metallic nano-rods in nano-optical system. Many research efforts are devoted to obtain the optical properties of metallic nano-rods. Optical extinction spectroscopy, scanning near-field optical microscopy (SNOM) and far-field Raman scattering by methylene blue are utilized to characterize the SPR on Au or Ag nano-rod. Since gold nano-rods can function as fundamental building blocks in plasmonic integrated optics, it is crucial to know their individual optical properties, especially the relationship between the incident light and the induced SPR modes on each single nano-rod. In this paper, to avoid the complexity of SNOM and the influence caused by the probe, we use simple polarization-contrast microscopy to attain far-field images of a single gold nano-rod. In particular, we find out the wave vectors of the induced longitudinal SPR modes from a gold nano-rod for its individual optical properties. Modulated standing modes resulted from the interference of longitudinal SPR modes and incident light are observed. By counting the average distance of adjacent beats on this single gold nano-rod, the wave vector of longitudinal SPR modes can be obtained. We found a linear relationship between the wave vectors of the incident light and the induced SPR modes. Experimental results demonstrate a feasible way on acquiring plasmonic optical properties from an individual single gold nano-rod. Instead of using gold nano-rods with various sizes, we utilize the same single gold nano-rod for the measurements to obtain its individual optical properties. Our experiments can be very useful for acquiring the individual optical properties of gold nano-rods or similar fundamental building blocks in complicated nano-devices of plasmonic nano-photonics. “TiO2 thin film coated optical fiber” (TTF-fiber) is a good media for transmission and allocation of light to induce photocatalytic reaction. Understanding the optical effect of the TTF-fiber is very important and benefit the optimized design for highest operation efficiency. In this paper, exponential decay rate of propagation light in TTF-fiber is calculated by beam propagation method (BPM). We can also obtain thickness of TiO2 thin film that reaches highest operation efficiency for the light source of UV-LED as well. We compare the difference on exponential decay rate of propagation light with various thicknesses of TiO2 on TTF-fiber. It shows that the Cu doping is not only change the energy level of TiO2 but also increase its metallic behavior. The surface plasmon resonance can be induced on the TiO2 thin film and increase the light-harvest efficiency. Therefore we can have Cu doped visible-light photocatalysis.目錄: 口試委員會審定書.............................................................................................................................. I 誌謝....................................................................................................................................................... II 中文摘要.............................................................................................................................................. III 英文摘要.............................................................................................................................................. V 第1章簡介 1.1 體積電漿共振......................................................................................................................5 1.2 表面電漿共振......................................................................................................................6 1.3 侷域表面電漿共振..............................................................................................................8 1.4 侷域表面電漿共振的應用.................................................................................................8 1.5 電漿共振波導....................................................................................................................11 1.6 電漿共振波導之耦合........................................................................................................12 第2章 奈米材料之合成 2.1 濕化學還原法合成奈米金球顆粒...................................................................................20 2.2 濕化學還原法之軟性模板合成奈米金棒......................................................................21 第3章 奈米金棒之表面電漿震盪耦合 3.1 偏振對比遠場光學顯微術...............................................................................................25 3.2 表面電漿波之與外加入射光之干涉...............................................................................27 3.3 表面電漿波之波向量量測...............................................................................................30 3.4 S偏振入射光誘發之表面電漿波....................................................................................35 第4章 奈米金棒波導之表面電漿震盪傳遞 4.1 表面電漿之傳遞................................................................................................................39 4.2 暗場光學顯微術................................................................................................................44 第5章 二氧化鈦光觸媒光纖介面波導 5.1 光觸媒光纖介面波導反應器...........................................................................................51 5.2 二氧化鈦光觸媒光纖之傳輸損耗估算..........................................................................54 5.3 不同光源之光觸媒反應器最佳化調整..........................................................................59 5.6 含銅光觸媒光纖介面波導...............................................................................................67 第6章 結論.........................................................................................................................................756674583 bytesapplication/pdfen-US表面電漿震盪奈米金棒表面電漿積體光學偏振對比顯微術紫外光發光二極體二氧化鈦光觸媒光纖可見光光觸媒surface plasmon resonanceAu nano-rodplasmonic nano-photonicspolarization-contrast microscopyUV-LEDphotocatalytic fibervisible-light photocatalysis[SDGs]SDG12thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/54661/1/ntu-96-D91222014-1.pdf