本文選題：手性負折射率材料 + 鐵磁材料　； 參考：《哈爾濱工業(yè)大學》2015年碩士論文

【摘要】：負折射率材料是將人工設計的幾何結(jié)構(gòu)單元與普通材料相結(jié)合,形成具有自然界材料所不具備的電磁性能的新型材料。該材料在軍事、醫(yī)療、生物科學、無線通信等領(lǐng)域有著巨大的應用前景。20世紀90年代末,負折射率材料的理論結(jié)構(gòu)及制作方法首次被提出并在實驗上成功實現(xiàn),越來越多的科研工作者將注意力集中在負折射率材料的研究中。在不斷的探索中,研究者們相繼提出了利用傳輸線結(jié)構(gòu)、光子晶體、手性結(jié)構(gòu)等實現(xiàn)負折射率的方式。其中手性負折射率材料由于其不需要同時實現(xiàn)負介電常數(shù)與負磁導率、結(jié)構(gòu)簡單易于制造、品質(zhì)因數(shù)高、折射率在結(jié)構(gòu)中漸變等優(yōu)點而成為實現(xiàn)負折射率的主要方法之一。近十年來所設計的負折射率結(jié)構(gòu)多數(shù)存在著應用頻帶窄、損耗大、可調(diào)諧性能差等問題。本論文針對這些問題,基于負折射率材料的設計理念,結(jié)合手性實現(xiàn)負折射率的方法,自行設計了一種基于電諧振機理的圓環(huán)形金屬諧振結(jié)構(gòu),通過數(shù)值模擬方法研究該結(jié)構(gòu)的透射、折射及可調(diào)諧性能,利用參數(shù)反演算法(包含Kramers-Kronig色散關(guān)系)研究該材料的有效電磁參數(shù)。通過改變結(jié)構(gòu)參數(shù)實現(xiàn)了負折射率頻帶的可調(diào)諧性能,通過分析負折射頻帶內(nèi)介電常數(shù)與磁導率不同時為負來探究手性結(jié)構(gòu)所起到的作用,并證明該結(jié)構(gòu)具有良好的旋光性能。分析在各個諧振頻帶下金屬內(nèi)部電場及表面電流分布情況,深入探究了該結(jié)構(gòu)的諧振機理。由于通過改變結(jié)構(gòu)參數(shù)來調(diào)諧負折射頻帶在實際應用中十分不方便,因此本論文運用鐵磁材料可實現(xiàn)負磁導率的特性,將鐵磁材料與所設計的負折射率結(jié)構(gòu)相結(jié)合形成復合結(jié)構(gòu),通過改變加載在鐵磁材料內(nèi)部的磁場強度來調(diào)節(jié)復合結(jié)構(gòu)的工作頻帶。首先將鐵磁材料匹配到已設計的簡單負折射率結(jié)構(gòu)上,依次改變鐵磁材料的厚度、兩者的匹配方式、外加磁場強度并進行數(shù)值模擬,分析各因素對復合結(jié)構(gòu)透射性、諧振性、工作頻帶可調(diào)諧性的影響,不斷優(yōu)化鐵磁材料的結(jié)構(gòu)參數(shù),探究鐵磁材料與負折射率材料的最佳匹配方式。對匹配后的復合結(jié)構(gòu)進行數(shù)值模擬,將模擬結(jié)果與未匹配鐵磁材料的負折射率結(jié)構(gòu)模擬結(jié)果進行對比,分析鐵磁材料對復合材料旋光性、損耗、諧振強度等性能的影響。本課題對具有多頻帶可調(diào)諧的性能的手性負折射率材料設計有著一定的參考價值,對推進手性負折射率材料的發(fā)展具有實際意義。
[Abstract]:Negative refractive index material is a new material which combines the geometric structure unit of artificial design and ordinary material to form a new material with electromagnetic properties that natural materials do not possess. The material has a great application prospect in military, medical, biological, wireless communication and other fields. The theoretical structure and system of negative refractive index materials in the late.20 of the 90s. More and more researchers focus on the study of negative refractive index materials for the first time, and more and more researchers focus on the study of negative refractive index materials. In the continuous exploration, the researchers have put forward the ways of realizing the negative ejection rate by using the structure of the transmission line, the photonic crystal and the chiral structure. It does not need to realize negative permittivity and negative permeability at the same time, the structure is simple and easy to manufacture, the quality factor is high, and the refractive index becomes one of the main methods to realize the negative refractive index. In the last ten years, most of the negative refractive index structures have the problems of narrow application frequency band, large loss and poor tunable performance. In order to solve these problems, based on the design idea of negative refractive index material and the method of realizing the negative refractive index of the chiral, a circular ring metal resonant structure based on the mechanism of electric resonance is designed, and the transmission, refraction and tunability of the structure are studied by the numerical simulation method, and the parameter inversion algorithm (including Kramers-Kronig color) is used. The effective electromagnetic parameters of the material are studied. The tunable performance of the negative refractive index band is realized by changing the structural parameters. By analyzing the role of the dielectric constant and the permeability in the negative refraction band, it is proved that the structure has good optical properties. The internal electric field and the distribution of the surface current in the lower metal are deeply explored. Because it is very inconvenient to tune the negative refraction band in the practical application by changing the structural parameters, the ferromagnetic material can be used to realize the characteristics of the negative permeability, and the ferromagnetic material is combined with the design of the negative refractive index structure. A composite structure is formed to adjust the working frequency band of the composite structure by changing the magnetic field strength loaded in the ferromagnetic material. First, the ferromagnetic material is matched to the designed simple negative refractive index structure, and the thickness of the ferromagnetic material is changed in turn, the matching mode of the two, the magnetic field strength and numerical simulation are carried out, and the complex factors are analyzed. The structure parameters of ferromagnetic materials are continuously optimized and the optimum matching mode of ferromagnetic materials and negative refractive index materials is investigated. The simulation results are compared with the negative refractive index structure simulation results of the unmatched ferromagnetic materials. The effect of ferromagnetic materials on the properties of the composites, such as the properties of optical rotation, loss and resonant strength, has a certain reference value for the design of the chiral negative refractive index materials with multi band tunable properties, and is of practical significance for the development of the chiral negative refractive index materials.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TB39

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相關(guān)期刊論文 前1條

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本文編號：1899893