非磁性隱形斗篷裝置的設計

近十幾年來，轉換光學不論是在理論或是實驗的發展都有非常成功的應用，人們可以用更廣義的空間座標轉換去控制光路，使得光學元件的設計更為方便與簡單，而其中一項很重要的應用就是本章所要討論的–「隱形斗篷」。在本論文中，我們建立在轉換光學已經證明的馬克士威方程式的不變性，得到了控制電磁波的材料參數，不過在理想斗篷內部的材料參數是非均勻、非等向性的，且在內邊界又出現參數發散至無窮大的奇異點問題，大大降低了實做的可能性，所以從基本研究開始，透過電磁波的波動方程式，在不改變其傳播路的情況下給予適當的簡化，也就是使用非磁性材料製作出來的隱形斗篷，將奇異點的問題解決以提高實現的可能性，但簡化的後果會付出阻抗不匹配的代價造成斗篷大量散射，因此如何透過轉換函數的設計，使阻抗能夠匹配以減少斗篷的散射及降低參數的大小以實現製作的可能性，成為本文的重點之一。而本論文的另一個重點，是透過光學轉換及互補材料的概念去隱形海市蜃樓，但其概念並非控制電磁波的行徑方向，而是用抵銷相位的概念去實行隱形的可能性，此隱形方式相對於另一種斗篷，優點為隱形之餘能使欲隱蔽的錯覺能夠與外界溝通，不過其在位置上的靈活度並不高，只能在單方向產生隱形的效果，所以為了解決此問題，我們將建立在此基礎上改變原隱形裝置結構成為一錯覺產生器，再利用此錯覺產生器來產生一隱形斗篷以解決上述問題並提供了實體裝置可不存在的優點。

關鍵字

隱形斗篷；轉換光學；阻抗匹配；非磁性

並列摘要

In recent ten years, transformation optics has been successful in not only theory but also experiment. People can control the optical path with the generalized coordinate transformation, and the designs of optical device become more easier and convenient. One of the important applications is what we will study in this paper –「invisibility cloak」. In this paper, we start from the invarient of Maxwell's equations which was already proved by transformation optics, and know the formula about the parameters of materials. The manufacture of ideal cloak is not easy to realize because the parameters of materials has the property with inhomogeneous and anisotropic. Apart from this, the parameters diverge to infinity when close to the inner boundary. We study from the basic which is called wave equation of electromagnetic waves, and hope to solve the problem about singularity with appropriate magnetic simplification that won't change the way of how electromagnetic wave propagate. There will pay for considerable scattering if we simplified the cloak, so how to design the transfomation fuction to match impedance for reducing scattering and lower the parameters will be the focus of this article. The another method for cloaking illusion will be carried out by transformation optics and complementary materials. However, the concept of the method implements through canceling out the phase of electromagnetic waves rather than controlling the propagation. The advantage relative to the foregoing is that illusion colud communicate with the wave, but do have the difficulty in cloaking at any direction. For solving this problem, we base on the original structure and reform it to be a illusion generator. So we can settle it down with illusion generator to project cloaking device and benefit from the non-necessity of materials in original position.

並列關鍵字

Invisibility cloak ； Transformation optics ； Impedance matching ； Non-magnetic

參考文獻

[1] J. B. Pendry, D. Schurig, and D. R. Smith, Controlling Electromagnetic Fields.

[2] U. Leonhardt, Optical conformal mapping.

Science, 2006.312：p.1777–1780.

[3] N. I. Landy and W. J. Padilla, Guiding light with conformal transformations.

Express, 2009.17：p.14872–14879.

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非磁性隱形斗篷裝置的設計

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