Research Of Optical Waveguides Based On Surface Plasmon Polaritons

Surface plasmon polaritons (SPPs) are surface collective charge oscillations that occur at the interface bewtwen conductors and dielectrics, which are bound to and propagate along conductor-dielectric interfaces. SPPs are evanescent waves and having the field components decaying exponentially into both neighboring media. The field of a plane SPP is paralled to the interface plane and perpendicular to the SPP propagation direction. Recently, there has been a gradual transition from fundamental studies to more application driven research in surface Plasmon nanophotonics. Thanks to many studies, a wide range of SPP-based optical elements and technologies have been developed, including data storage, optical antenna, solar cell, biosensor, and more. SPPs can be tightly bound to the metal/dielectric interface, penetrating on the order of100nm into the dielectric and-10nm into the metal. This feature implies the potential of using SPPs for miniature optical circuits and has attracted a great deal of attention. In this thesis, we demonstrated our research on subwavelength optical devices based on SPP. Our work includes maily the following five parts:1. Dispersive model for metal are concluded, and kinds of numerical methods are discussed. The transfer matrix method (TMM) and cauchy integral method are used for SPP planar waveguide. The finite element method (FEM) and finite different time domain (FDTD) method are used to design and optimize SPP optical devices.2. Silicon based hybrid plasmonic waveguide (HPW) is demonstrated, which is a metal-oxide-silicon structure. The HPWs, which consists of a high index dielectric layer, a thin metal layer and a low index dielectric layer between them, exhibits not only good light confinement ability in nanoscale, but also low propagation loss and potential compatibility with CMOS technology.3. SPP based optical devices are proposed and analyzed. Combined the slot structure, a theoretical analysis about TE polarized hybrid plasmonic bragg grating is presented. Moreover, a defect is introduced into Bragg grating. The Multimode interference and microring resonant for TM polarized hybrid plasmonic optical deviced are also fully analyzed. 4. TM polarized hybrid plasmonic optical devices are fabricated on SOI platform with electron beam lithography (EBL) and inductive coupling plasma reactive ion etching (ICP RIE). A compact, highly efficient and low crosstalk hybrid plasmonic waveguide crossing is proposed and experimentally demonstrated.5. Passive plasmonic optical devices are discussed. Using graphene as the active medium, a new electro-refractive Mach-Zender interferometer based on the Graphene-Oxide-Silicon structure is presented. And the graphene plasmonic devices and graphene assisted MOS passive optical devices are also demonstrated. With the quantum theory, the PT based plasmonic structures are also proposed.The work of this thesis mostly based on the basic aspects of SPP waveguide, from theory research to experiment improvement. The thesis is intended to provide a reference for the following research of plasmonic integration.