本文關鍵詞：多切口金納米圓環(huán)陣列光學特性研究　出處：《陜西師范大學》2015年碩士論文　論文類型：學位論文

  更多相關文章： 局域表面等離激元共振 光學特性 圓二色性 有限元方法

【摘要】：表面等離激元(surface plasmon, SP)是金屬表面自由電子和入射電磁場之間相互作用形成的一種電磁模。依據其表現形式可以將其分為沿著金屬表面?zhèn)鬏數谋砻娴入x極化激元(Surface Plasmon Polaritons, SPPs)和不能傳播的局域表面等離激元(Localized Surface Plasmon, LSP)。貴金屬納米粒子的遠場和近場特征主要源自納米粒子的局域表面等離激元共振(Localized Surface Plasmon Resonance, LSPR)。研究發(fā)現,金屬表面的LSPR特性與金屬納米粒子的形狀、大小、組分以及周圍媒質等因素有關。此外,LSP在納米顆粒表面特定區(qū)域的電場增強效應,使得許多光學過程的效率顯著提高,這一特性使其在表面增強拉曼散射、非線性光學、生物醫(yī)學等方面有廣泛的應用。近年來,金屬手性微納結構在眾多領域廣泛應用,其表面等離激元共振特性能引發(fā)的特殊的光學性質。本論文采用有限元方法研究了多切口金納米圓環(huán)(MSR)陣列、雙層多切口金納米圓環(huán)(BMSR)陣列及旋轉的BMSR陣列的光學性質。具體內容及結果如下：(1)應用有限元方法研究了MSR陣列的LSPR特性,并研究了偏振狀態(tài)、結構參數改變對其LSPR特性的影響。結果表明,當入射光偏振角度變化時,MSR陣列的透射光譜不發(fā)生改變,但其表面電場強烈依賴于入射光偏振角度。當MSR結構參數改變時,圓弧縱橫比發(fā)生變化,透射光譜發(fā)生紅移或藍移。(2)提出了一種雙層結構——BMSR陣列結構,研究其在線偏振光照射下透射谷產生的物理機制,并計算了入射光偏振角度、結構參數改變時其透射光譜的變化。研究表明,雙層結構對于單層結構來說,多出一種磁共振模式,該結構在此模式下可以等效為LC回路。入射光偏振角度的變化不影響B(tài)MSR陣列的透射光譜。各結構參數改變時,兩種共振模式發(fā)生紅移或藍移。(3)旋轉的BMSR是一種手性結構,本文研究該結構在圓偏振光照射下的圓二色性(circular dichroism, CD)。通過改變下層旋轉角度發(fā)現較強的CD效應出現在三個波段,對一個CD峰處該結構上下層電流分析得出CD效應產生的原因。此外,我們還研究了結構參數對旋轉的BMSR陣列CD效應的影響。
[Abstract]:The surface plasmon (surface plasmon SP) is a kind of electromagnetic modes of interaction formed between the metal surface and the free electron incident electromagnetic field. On the basis of the form can be divided into the metal surface along the transmission surface plasmon polariton (Surface Plasmon, Polaritons, SPPs) and not the spread of localized surface plasmon polaritons (Localized Surface Plasmon, LSP). Noble metal nanoparticles far field and near field characteristics mainly from nanoparticles localized surface plasmon resonance (Localized Surface Plasmon Resonance, LSPR). The study found that the LSPR characteristics and the metal nanoparticles of metal surface shape, size, related components and the surrounding medium etc.. In addition, in the specific area of electric field enhancement effect of LSP nano particle surface, make the efficiency of many optical process significantly improved, this character makes it in surface enhanced Raman scattering, non Linear optics, has been widely used in biomedical fields. In recent years, the chiral metal micro nano structure is widely used in many fields, special optical properties caused by the surface plasmon resonance properties. The nano gold ring incision using the finite element method in this paper (MSR) array, multi incision double gold nanoparticles ring (BMSR) optical properties of array and BMSR array rotation. The contents and results are as follows: (1) the finite element method is applied to study the LSPR characteristics of MSR array, and studied the polarization states and the effect of structure parameters on the LSPR performance. The results show that when the change of the polarization of the incident light angle, transmission spectrum the MSR array is not changed, but the surface electric field is strongly dependent on the polarization of the incident light angle. When changing the MSR structure parameters, arc aspect ratio change, transmission spectral redshift or blueshift. (2) proposed a double The structure of BMSR array structure, study its physical mechanism by a linearly polarized light transmission Valley is generated, the polarization of the incident light angle was calculated, changes in the transmission spectrum of the changing structural parameters. The results show that the double-layer structure for single layer structure, a kind of magnetic resonance mode, the structure of this mode is equivalent to LC loop. Change the polarization of the incident light angle does not affect the transmission spectrum of the BMSR array. Changing the structure parameters, two resonance modes occur red shift or blue shift. (3) the rotation of the BMSR is a chiral structure, this paper studies the structure of the circular polarized light under the irradiation of round two color (circular dichroism CD) by changing the lower rotation angle found strong CD effect appeared in three bands, the structure of upper and lower current cause of the CD effect of a CD peak. In addition, we also study the structural parameters of the spin The effect of the CD effect on the BMSR array.

【學位授予單位】：陜西師范大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TB383.1

【參考文獻】

相關期刊論文 前1條

1 李杰;楊方清;董建峰;;雙層金屬線平面手征結構的強旋光性和負折射率研究[J];物理學報;2011年12期

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本文編號：1412612