The Surface Plasmon Energy Bands And Spread Of The Nature Of The Periodic Structure

Surface plasmon polariton(SPP) is a kind of electromagnetic excitation existing on metallic surfaces. Many theoretic research and applications are ongoing to take advantages of SPPs such as subwavelength nature, high field intensity and low dimensionality. Now SPP is a footstone of plasmonics, which is an emerging branch of photonics. The central idea of all the research is to explain and uncover the fundamental physics and possible values of SPPs propagating on smooth and corrugated surfaces. We're also trying to do further study based on this idea. The thesis consists of four chapters.In chapter 1 the main properties of SPPs are described, including dispersion relation, field distribution and propagation length. SPPs can be excited by electrons or by light. Then a triumph of plasmonics: SPP induced extraordinary transmission through subwavelength holes is introduced. Illuminated by this extraordinary light, we find a new approach to excite SPP and corrugated dielectric structures come out instead of textured metallic surfaces.In chapter 2 we give an introduction to FDTD and transfer matrix methods which are the commonly used algorithms in this thesis. We have developed many additional methods to deal with some complicated systems starting from transfer matrix. We've sketched the logic and given some derivations.Chapter 3 begins with the dispersion of SPP on metallic film, and tries to make the best use of dielectric-metal multilayer structure. We have proved the existence of Brewster angle at the metallic-dielectric interface. And the high transmission of infrared light due to Brewster angle is found by chance. The simple application is to make a novel infrared polarizer.The main work of this thesis is shown in chapter 4. We firstly propose a new kind of structure: corrugated dielectric layer on top of smooth metallic surface or film, which provides a novel way to mold the dispersion and propagation of SPPs. We introduce symmetric dielectric layers on both sides of metallic film and find the similar extraordinary transmission phenomena. To understand the physics more profoundly, we discuss how the band structures of SPPs depend on the dielectric parameters with effective medium method and photonic crystal approximation. Guided modes and corresponding enhanced transmission and absorption can be observed in this system. Two processes in the time domain are found when SPPs are excited, one is direct and another indirect. We show the reflection and transmission behaviors when SPPs propagate along the metallic surface with one dimensional dielectric layer coated.