Optical Properties Of 2D Photonic Crystal Monolayer Based On Surface Plasmon

Since the discovery of extraordinary transmission in subwavelength hole arrays in metal film in 1998, researchers around the world have aroused a great deal of interest, because its potential applications in subwavelength photoelectric devices and basic physics. It has become a hotspot both at home and abroad, and has very broad scientific significance and applications.Although the exact causes of the extraordinary transmission is still controversial, but the surface plasmon (SPPs) which played a key role is already widely recognized. Recently, study indicate that this phenomenon may be the diffraction support behavior of SPPs. The object of this thesis is surface plasmon device with photonic crystal structures. We research the mechanism of this extroardinary transmission phenomenon, analyzes the device design factors and explore their optical properties and potential applications in the sensing area.This thesis is divided into the following chapters:The first chapter introduces the background knowledge. First, we describe the definition, research history, mechanism, characteristics, coupling mode and physical meaning of the surface plasmon. Then, we introduce the concept and development process of photonic crystals. Finally and most importantly, the transmission behavior of photonic crystal based surface plasmon substrate of and its background.The second chapter is the preparation and design of the photonic crystal based SPR device. In this experiment we use the emulsion polymerization method for the synthesis of polystyrene sodium particles of uniform size, and prepare two-dimensional array of polystyrene spheres monolayer substrate through the air-liquid interface self-assemble. Finally, we deposit a certain thickness of metal film on the substrate through vacuum evaporation deposition. And characterize their optical properties with UV - visible - near infrared spectroscopy.The third chapter is the mechanism analysis and spectral detection of the device. We detect the reflection and transmission spectrum and discuss the causes and mechanisms of the peak in the spectrum. We change the incident angle to detect the changes in the spectrum with the angle, and explain the mechanism through Bragg diffraction theory and the plasmon. The main design factors are photonic crystal lattice constant, metal species and metal film thickness of the substrate.The fourth chapter is the sensing capacity to the refractive index of the device. We detect the spectrum under different angles in different refractive index environment, and obtain refractive index - peak curve under different angles. Then we calculate through the curve and obtain the maximum sensitivity through comparison.