【摘要】：金屬納米結(jié)構(gòu)中局域表面等離子激元共振的現(xiàn)象在過(guò)去幾十年中得到人們的極大關(guān)注。研究表明，金屬納米結(jié)構(gòu)的光學(xué)性質(zhì)取決于局域表面等離激元共振。而局域表面等離激元共振具有近場(chǎng)增強(qiáng)大、對(duì)外部環(huán)境變化敏感、可突破衍射極限等特性，在生物傳感、表面增強(qiáng)拉曼散射、慢光傳輸、納米天線(xiàn)、非線(xiàn)性增強(qiáng)等很多領(lǐng)域都有重要的應(yīng)用前景。然而，隨著顆粒尺寸的增大，輻射衰減極大增強(qiáng)，造成譜線(xiàn)線(xiàn)寬的增大，不利于上述應(yīng)用性能的提高。 表面等離激元Fano共振是超輻射明態(tài)和弱輻射暗態(tài)之間的相消干涉所引起的。由于暗態(tài)的激發(fā)，可以有效抑制體系輻射衰減，形成精細(xì)的譜線(xiàn)，并增強(qiáng)近場(chǎng)，從而提高如生物傳感質(zhì)量因子等應(yīng)用的性能。當(dāng)體系具有多個(gè)弱輻射暗態(tài)，它們與超輻射明態(tài)的耦合可引起多重Fano共振的產(chǎn)生。利用多重Fano共振，可在多個(gè)波段同時(shí)調(diào)制光譜，降低輻射展寬，這對(duì)多波長(zhǎng)傳感等應(yīng)用具有重要意義。本文提出暗態(tài)間的表面等離激元耦合是產(chǎn)生Fano共振的一種有效方法。根據(jù)等離激元雜化理論，暗態(tài)耦合將形成成鍵弱輻射模式和反成鍵弱輻射模式。當(dāng)這兩種雜化暗態(tài)與明態(tài)形成耦合，將在光譜中出現(xiàn)多重Fano共振的現(xiàn)象。 本文設(shè)計(jì)了一種由同心納米環(huán)構(gòu)成的二聚體共振腔結(jié)構(gòu)。研究表明，，在不破壞體系對(duì)稱(chēng)性的條件下，納米環(huán)之間的相互作用可直接激發(fā)起四極共振模式，兩個(gè)納米環(huán)四極模式的耦合形成了成鍵弱輻射雜化模式，從而引起光譜中Fano共振的出現(xiàn)。當(dāng)上述二聚體結(jié)構(gòu)中兩個(gè)內(nèi)環(huán)向相同的方向偏移時(shí)，即當(dāng)整個(gè)結(jié)構(gòu)的對(duì)稱(chēng)性被打破后，還可激發(fā)起反成鍵弱輻射模式。成鍵弱輻射模式和反成鍵弱輻射模式的形成導(dǎo)致了雙重Fano共振的產(chǎn)生。
[Abstract]:The phenomenon of local surface plasmon resonance in metal nanostructures has attracted much attention in the past few decades. It is shown that the optical properties of metal nanostructures depend on the local surface isoexciton resonance. The local surface isoexciton resonance has the characteristics of large near-field enhancement, sensitive to changes in the external environment, and the ability to break through the diffraction limit. It can enhance Raman scattering on the surface, slow light transmission, nano-antenna, and so on. Nonlinear enhancement and many other fields have important application prospects. However, with the increase of particle size, the radiation attenuation is greatly enhanced, resulting in the increase of line width, which is not conducive to the improvement of the performance of the above applications. The Fano resonance of surface isotherm is caused by the interference between superradiance and weak radiation dark state. Because of the dark state excitation, the radiation attenuation of the system can be effectively suppressed, the fine spectral lines can be formed, and the near field can be enhanced, thus improving the performance of applications such as the biosensor quality factor. When the system has several weak radiation dark states, their coupling with superradiance can lead to multiple Fano resonance. The multiplex Fano resonance can modulate the spectrum at the same time in multiple wavelengths and reduce the radiation broadening, which is of great significance for the application of multi-wavelength sensing and so on. In this paper, an effective method for generating Fano resonance is presented. According to the theory of isotherm hybridization dark state coupling will form bond weak radiation mode and inverse bond weak radiation model. When the two hybrid dark states are coupled with the open state, there will be multiple Fano resonance in the spectrum. A dimer resonator structure composed of concentric nanorings is designed in this paper. The results show that the interaction between the nanometers can directly excite the quadrupole resonance mode without breaking the symmetry of the system, and the coupling of the two quadrupole modes forms the bonding weak radiation hybrid mode. Thus, Fano resonance appears in the spectrum. When the two inner loops of the dimer move in the same direction, that is, when the symmetry of the whole structure is broken, the weak radiation mode of the inverse bonding can be excited. The formation of bonding weak radiation mode and anti-bonding weak radiation mode leads to the formation of double Fano resonance.
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TB383.1;O631

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 李志遠(yuǎn);李家方;;金屬納米結(jié)構(gòu)表面等離子體共振的調(diào)控和利用[J];科學(xué)通報(bào);2011年32期

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