近幾年來，在超材料(metamaterials)相關研究上，不僅發現了許多新的物理現象，也有不少的微波光電元件也因應而生。其中最特別的，如人造磁性、負折射率、完美成像、指向性出射等等，也已經被人們以人造超材料實現。

　　在本論文中，我們以實驗驗證了金屬微線光子晶體結構具有負的介電係數、非連續環結構(Split-ring resonator, 簡稱SRR)具有負磁導係數以及在折射穿透實驗中我們也驗證了左手材質具有負折射率。利用時域量測我們發現了左手超材料具有異常的相位前移現象。

　　伴隨著新式超材料的快速發展，世界各地研究者提出了許多新穎的想法與光電元件概念，其中最引人注目的莫過於J. B. Pendry 於西元2000年所提出的完美成像。我們的實驗證明了完美成像的可行性，我們的電磁模擬結果也與實驗結果相符。

　　另一個神奇的超材料應用是Enoch 等人於西元2002 年提出的指向性出射。Enoch 等人利用Snell 定律的概念證明當超材料的折射率大於0 但遠小於1 時，從這種超材料中所發出的光會呈現指向性出射，我們的實驗與模擬結果發現這種指向性出射與超材料的結構參數與厚度有關，不能單單以Snell 定律來描述。在次波長尺度下，我們也提出組合互補金屬遮幕與次波長孔徑以達成指向性發射，並同時具有穿透放大效應與可調共振頻率效應。

　　為了將超材料的應用波長延伸至更短的波段，我們也設計了另一種變型不連續環結構(deformed SRR, 簡稱DSRR)。 DSRR 簡化了原先SRR 的設計並使得其尺寸比SRR 縮小將近5 倍，使其更適用於短波長波段之應用，我們的實驗結果顯示DSRR 具有負的磁導係數。

　Recent research activities on metamaterials have not only discovered many newphysical phenomena, but have also realized new microwave photonic devices. In particular, artificial magnetism, negative refraction index, perfect imaging, directive emission are new types of behavior that have been demonstrated over the past few years.

　In this dissertation, we have experimentally demonstrated the negative permittivity property of wires array structure, the negative permeability property of split-ring resonators array structure in microwave X-band. A de°ection experiment in the frequency of microwave X-band was performed and the experimental resutls veri¯ed the negative refraction index of left-handed media, composed of wires and split-ring resonators structure with both the permittivity and permeability negative. By time-domain measurement of the microwave beam propagating through layers of left-handed media, we
demonstrated the speci¯c phenomenon of phase advancing in those man-made materials, and found an anomalous phase advancing related to the sample thickness.

　Accompanying the rapid development of new metamaterials, many new idea of interesting electromagnetic phenomena and devices were proposed. One of its promising optical components is the perfect lens, proposed by J. B. Pendry in 2000, which was shown the ability of breaking the di®raction limit of conventional lens. We have experimentally demonstrated the perfect imaging ability of a planar left-handed media with mu = -1, epsilon = -1, and thus n = -1 in free space. Our simulation results also agreed with our experimental results, thus verifying the idea of perfect lens which has been argued in recent years.

　Another novel phenomenon of metamaterials is the directive emission when the optical properties of materials is with positive refraction index but close to zero, which is an important issue in the design of antenna. In 2002, Enoch et al. showed that metallic grid slab with effective index of refraction n ~ 0 can modify the emission of
an embedded source with experimental demonstration in microwave domain. Enoch et al. provided an intuitive interpretation of directive emission based on the Snells law. Besides the Snell law's interpretation, we showed that directive emission has close connection to its diffraction nature.

　To extend the directive emission into subwavelength scale, we proposed an alternative method to accomplish the capacities of Enhanced transmission, wavelength selection and directive emission through a single subwavelength aperture. To be specific, we
introduced a complementary metal screen in front of a single subwavelength aperture.
By tuning the distance between the complemental metal screen and the subwavelength aperture, resonant wavelength of enhanced transmission and directive emission can be designated precisely.

　While most experimental work on metamaterials has been done at microwave X-band, it will be exhilarating to extend the phenomena to infrared and even visible frequencies, which will greatly increase the range of applications, e.g. perfect lens, directive emission devices. One of the key points is how to design a miniature structure applicable in optical wavelength. We have design a structure of deformed split-ring resonators, which minimizes the size of the unit cell for fabrication, which is favorable for the implementation of left-handed metamaterial in near infrared region.

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