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Doctoral Thesis / Dissertation from the year 2008 in the subject Physics - Optics, Babe -Bolyai Universit, language: English, abstract: Ordered plasmonic nanostructures are currently the subject of numerous scientific studies, due to their potential applications, from optical communications to chemical analyses and biomedicine. This thesis is focused on a special type of periodically ordered two-dimensional (2D) metallo-dielectric structure, noble metal films over microsphere arrays: from their fabrication and characterization, to spectroscopic applications. Prepared structures exhibit remarkable optical properties (including an unusually high transmittance, resembling the extraordinary optical transmission phenomenon), resulting from the excitation of surface plasmons. It is demonstrated that these plasmo-photonic structures are very promising multifunctional active-substrates for Surface Enhanced Raman Scattering, Metal Enhanced Fluorescence, and Surface Plasmon Resonance Spectroscopy.
Chapter 1 is devoted to giving an overview of the interesting aspects related to the optical properties and applications of periodically structured metals and dielectrics. We also briefly describe some of the currently developed nanofabrication techniques. A few concepts, like the photonic band and surface plasmon are introduced, being useful for the discussions in the upcoming chapters. We pay a special attention to colloidal photonic crystal films and noble metal structures obtained by templating on two-dimensional colloidal crystals. Chapter 2 presents own experimental results concerning the preparation, characterization and lithographic applications of two-dimensional (2D) colloidal crystal films. Results of the optical properties investigations are presented in Chapter 3, and divided in two main categories: i) photonic properties of bare microsphere arrays, and ii) plasmonic properties of noble metal nanostructured films deposited over microsphere arrays. In Chapter 4 we explore the capabilities of noble metal coated microsphere arrays to improve the sensitivity of optical spectroscopic methods: Surface Enhanced Raman Scattering, Metal Enhanced Fluorescence, and Surface Plasmon Resonance Spectroscopy.
