Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/50160
標題: Study and Application of Steering the Transmission Characteristics of Electromagnetic Waves Using Transformation Optics
變換光學在調控電磁波傳輸特性上的研究與應用
作者: 黃家健
關鍵字: 光電工程
應用研究
摘要: Recently, the metamaterials with anisotropic and inhomogeneous properties are proposed and designed by using transformation optics theory. By controlling the wavefront of electromagnetic waves, the object inside the metamaterials has no interaction with the electromagnetic waves outside the metamaterials. The object can be therefore hidden by the metamaterials and exhibits the invisible phenomenon. According to this idea, we can effectively modulate and control the transmission path of electromagnetic waves.As a result, using the Schwarz-Christoffel conformal mapping theory, we first intend to find out the appropriate coordinate transformations to systematically study the metamaterials in designing the ideal invisibility cloak with arbitrary shape. Besides, we also discuss the variations of the transmission characteristics of electromagnetic waves by some little disturbances of the metamaterials.Theoretically, we cannot obtain the ideal invisibility cloak by only considering the reduced parameters. Besides, the impedance match condition cannot be achieved due to the use of reduced parameters. Through the introduction of the quadratic form of coordinate transformation, the impedance can be matched to the air. However, the geometrical shape for designing the cloak is constrained. Therefore, we expect to find the solution to release the design limitation by numerical modeling or analytical approach. Additionally, we intend to study the relations of using the reduced parameters and the tangent loss to the scattering of electromagnetic waves. We expect to construct the desired characteristics through only applying the dielectric materials. In this manner, the metamaterials can be fabricated using the mature nano-lithography technique.For designing the invisibility cloaks, the coordinate transformations show a sort of expanding-type. Conversely, to steer and focus the electromagnetic power to a localized zone, we obtain the coordinate transformations with convergent type. Using the transformations with convergent type, we intend to analyze the insertion and radiation losses of optical power. Once the results are obtained, it's useful to integrate the nano-optical devices onto the present integrated circuits with nano scale.
最近利用變換光學理論設計出各種具異向性與非均勻的超穎材料,藉由控制經過此材料的電磁波前,使得覆於這些材料內的物體不會與材料外的電磁波產生交互作用,進而達到隱形的功能,有效地控制能量的傳輸路徑。有鑑於此,首先我們計劃利用Schwarz-Christoffel保角變換理論,藉著找出合適的座標轉換形式,有系統地研究可用以設計任意形狀之理想隱形斗篷的超穎材料,並研究超穎材料中微小擾動造成電磁傳輸特性的變化程度,以推廣至更廣泛的應用。若考慮使用簡化參數,已經無法完美隱形,並且無法達到斗篷的外殼與空氣中的阻抗匹配,經由二階變換式的修正,達到阻抗匹配,但斗篷的幾何條件受限,因此我們希望利用數值模擬或解析的方式,解決斗篷設計上的幾何限制,並研究簡化參數與材料的損耗性對電磁波散射的影響,並考慮是否僅使用介電質材料即可建構出所需的電磁波傳輸特性,如此將可結合成熟的奈米級矽蝕刻技術,以利材料製作。除此之外,由於設計隱形斗蓬使用的是擴展型座標變換形式,相反地,我們希望利用收縮型座標變換用以聚焦與調控電磁波的能量,使得我們可以控制光波能量的傳播路徑,並分析減少光波的插入損耗與輻射損耗的問題,將理論分析的結果應用到各種實用的奈米光路上,如此將有助於整合奈米光元件至現今奈米級的積體電路元件上。
URI: http://hdl.handle.net/11455/50160
其他識別: NSC99-2112-M005-005-MY3
文章連結: http://grbsearch.stpi.narl.org.tw/GRB/result.jsp?id=2144639&plan_no=NSC99-2112-M005-005-MY3&plan_year=99&projkey=PB9907-9931&target=plan&highStr=*&check=0&pnchDesc=%E8%AE%8A%E6%8F%9B%E5%85%89%E5%AD%B8%E5%9C%A8%E8%AA%BF%E6%8E%A7%E9%9B%BB%E7%A3%81%E6%B3%A2%E5%82%B3%E8%BC%B8%E7%89%B9%E6%80%A7%E4%B8%8A%E7%9A%84%E7%A0%94%E7%A9%B6%E8%88%87%E6%87%89%E7%94%A8
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