近年來，表面等離子體因為可以在金屬表面激發極強的局部電磁場而受到廣泛的關注。它是光和物質之間的重要的聯繫。基於它在納米量級上操控和引導光子的能力，表面等離子體已廣泛應用于納米和生物光學之中，比如生物傳感器，表面增強拉曼散射，光鑷，發光二極管，太陽能電池和超材料等等。然而，儘管系統結構，材料特性，激發光波長和條件都會影響表面等離子體本身的特性以及它與材料之間的相互作用，這些外部條件的整體效果卻常常不為人所知。更重要的是，在表面等離子體和這些外部條件之間，似乎仍有未知的聯繫存在。比如，現在人們仍然不是很清楚激發表面等離子體的納米結構到底是怎樣控制它以及與它相關的特性的。 / 在這篇論文里，我們希望通過耦合模理論將這些外部條件和表面等離子體特性聯繫起來。耦合模理論提供了表面等離子體吸收和輻射壽命等內部參數以及它們與光相位，振幅，傳播方向的關係。因為這些外部條件和壽命參數，激發條件之間的聯繫廣為人知，我們因此就可以把這些外部條件和表面等離子體特性聯繫起來了。一旦獲得了這些壽命參數，我們亦可從另外一個角度研究表面等離子體的基本特性。比如，我們發現兩個簡併表面等離子體耦合除了形成超模式和次模式以外，它們的輻射壽命和吸收壽命都發生了改變。另外，我們在實空間和動量空間研究了表面等離子體衰變長度，群速度等其他內部參數，并發現它們和等離子體衰減及態密度有重要聯繫。我們還發現基於相位躍變的表面等離子體傳感器在臨界耦合時將獲得最優表現。最後，通過研究發光材料和表面等離子體之間的耦合效率，我們發現態密度在其中起了關鍵作用。 / Surface plasmons (SPs), which generate strong localized electromagnetic fields at metal surface, have been capturing worldwide attention recently because they establish an important link between light and matter. Due to their ability to route and manipulate photon at the nanoscale, SPs have been widely used in nano- and bio-photonics including biosensor, surface enhanced Raman scattering, optical tweezers, light emitting diodes, solar cell, and metamaterials, etc. However, although it is known that system geometry, material, wavelength, excitation condition are important in governing the behaviors of SPs as well as matter/SPPs interactions, how they work together in producing the final outcome is largely unknown. More importantly, there seems to be a "missing link" between these extrinsic parameters and the properties of SPs such that, for example, it is still not quite understood the exact roles of geometry play in controlling the SPs and their related properties. / In this thesis, we aim at bridging the link between extrinsic parameters and SPs properties based on temporal coupled-mode theory (CMT). CMT provides the knowledge of intrinsic parameters such as SPs radiative and absorption rates and their relationships with the phase, amplitude, and directionality of SPs. Because decay rates are strong function of system parameters, excitation condition, etc, connection between the extrinsic parameters and the SPs properties can now be established. With the decay rates and other accessories in hand, we study the fundamental of SPs from another perspective. For example, we examine how two degenerate SPs modes couple to yield a pair of dark and bright modes and find not only the radiation damping of SPs but also the absorption are modified. In addition, we study the decay length and the group velocity of SPs in real- and momentum- space to elucidate the interplay between the SPs losses and the wavevector-resolved projected density-of-optical-states (PDOS). We also explore the rate matching (i.e. critical coupling) for optimizing the phase-jump in SPs resonance sensing and achieve high figure of merit in sensing performance. Finally, the coupling between SPs and light emitters has been studied and it is found that their coupling rate is governed by PDOS. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Cao, Zhaolong = 表面等離子體激元在金屬納米洞陣列上的衰變研究及其應用 / 曹兆龍. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 142-149). / Abstracts also in Chinese. / Cao, Zhaolong = Biao mian deng li zi ti ji yuan zai jin shu na mi dong zhen lie shang de shuai bian yan jiu ji qi ying yong / Cao Zhaolong.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_1077717 |
| Date | January 2014 |
| Contributors | Cao, Zhaolong (author.), Ong, Hock Chun Daniel (thesis advisor.), Chinese University of Hong Kong Graduate School. Division of Physics, (degree granting institution.) |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography, text |
| Format | electronic resource, electronic resource, remote, 1 online resource (xxiii, 149 leaves) : illustrations (some color), computer, online resource |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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