本文選題：太赫茲　切入點：超材料　出處：《電子科技大學》2016年碩士論文

【摘要】：近年來,超材料的研究覆蓋了眾多領域,從微波波段到可見光波段,從基礎研究到應用研究。最近,超材料在非線性、可增益、動態(tài)可調、光轉換以及量子等方面取得的新進展,使超材料成為研究一些特殊物理現(xiàn)象的一個豐富多彩的媒介,并為光子學器件的突破性發(fā)展奠定了基礎。另一方面,4-(4-二甲基氨基苯乙烯基)甲基吡啶對甲基苯磺酸鹽(簡稱DAST)是一種非常重要的有機材料,具有顯著的雙折射效應、橫向光學聲子、電光效應以及二階非線性效應,在太赫茲發(fā)射、探測領域,以及高速電光調制、電光采樣、集成光波導等光學集成器件領域具有廣闊的應用前景。本論文中,通過將DAST晶體與超材料結構相結合,作為超材料的介電層,得到以下結果:(1)將DAST晶體作為超材料的介電層,利用DAST晶體的雙折射效應,實現(xiàn)了響應頻率隨入射光偏振方向變化的超材料。仿真結果表明:本論文設計的超材料結構,其響應頻率可在1.54THz到2.07THz范圍內變化,變化范圍達到29%。(2)利用DAST晶體在1.1THz處的橫向光學聲子,將DAST的分子振動與超材料的結構振動集成到一個系統(tǒng)中。仿真結果表明:DAST超材料耦合系統(tǒng)屬于光與物質的強耦合,系統(tǒng)的真空Rabi分裂頻率為0.37THz,是本征振動頻率1.1THz的31%。仿真得到的隨超材料結構尺寸變化的分裂峰,其分布曲線與理論計算預測結果吻合得很好。(3)首次成功地制作出DAST多晶超材料,并進行了太赫茲響應測試。結果表明,在響應頻率1.04THz處,超材料的吸收率達50%。此外,在原有的Al/Si襯底基礎上,引入圖形化SiO2層后,DAST薄膜的平整度獲得明顯改善,DAST多晶超材料的響應得到增強,吸收率達到60%。(4)在DAST多晶超材料中,發(fā)現(xiàn)了DAST分子振動與超材料上下金屬層之間的F-P腔共振耦合,從實驗上觀測到了分子振動引入透過現(xiàn)象。(5)首次成功地制作出DAST單晶超材料,并從實驗上觀測到DAST分子振動與超材料結構之間的強耦合,以及DAST晶體的各向異性對超材料響應的影響。這些研究成果,在一定程度上,發(fā)掘了DAST晶體的應用潛力,拓展了超材料的研究范圍;同時,為光與物質的耦合相關基礎物理學理論的研究,提供了一個可行的實驗方案及證明。
[Abstract]:In recent years, the research of metamaterials has covered many fields, from microwave band to visible wave band, from basic research to application research. New advances in optical conversion and quantum have made metamaterials a colorful medium for the study of specific physical phenomena. It also lays a foundation for the breakthrough development of photonics devices. On the other hand, 4-dimethylaminophenylvinyl) pyridine p-methylbenzene sulfonate (DAST) is a very important organic material with remarkable birefringence effect. Transverse optical phonons, electro-optic effects and second-order nonlinear effects have broad application prospects in the field of terahertz emission, detection, high-speed electro-optic modulation, electro-optic sampling, integrated optical waveguide and other optical integrated devices. By combining DAST crystal with metamaterial structure as the dielectric layer of supermaterial, the following results are obtained: 1) the DAST crystal is used as the dielectric layer of metamaterial, and the birefringence effect of DAST crystal is utilized. The supermaterial whose response frequency varies with the polarization direction of incident light is realized. The simulation results show that the response frequency of the metamaterial structure designed in this paper can vary from 1.54THz to 2.07THz. Using the transverse optical phonon of DAST crystal at 1.1THz, the molecular vibration of DAST and the structural vibration of metamaterials are integrated into a system. The simulation results show that the coupling system of DAST supermaterial belongs to the strong coupling of light and matter. The vacuum Rabi splitting frequency of the system is 0.37 THZ, which is the 31th peak of the intrinsic vibration frequency 1.1THz. The distribution curve of DAST polycrystalline supermaterial obtained by simulation is in good agreement with the predicted results of theoretical calculation. The terahertz response test was carried out. The results show that the absorptivity of the supermaterial reaches 50% at the response frequency 1.04THz. In addition, on the basis of the original Al/Si substrate, The flatness of Dast film was improved by introducing graphical SiO2 layer. The response of Dast polycrystalline supermaterial was enhanced, and the absorptivity reached 60%. In DAST polycrystalline supermaterial, the resonance coupling between DAST molecular vibration and the upper and lower metal layers of the supermaterial was found. In this paper, we have observed experimentally the phenomenon of molecular vibration introducing transmission. (5) the DAST single crystal supermaterial has been successfully prepared for the first time, and the strong coupling between the molecular vibration of DAST and the structure of the supermaterial has been observed experimentally. And the effect of anisotropy of DAST crystal on the response of metamaterials. To some extent, these results have explored the application potential of DAST crystals and expanded the research scope of metamaterials. It provides a feasible experimental scheme and proof for the fundamental physics theory of the coupling of light and matter.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TB34

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本文編號：1665075