Study on the Characteristics of Surface Plasmon Coupling with a Dipole in Air/metal/dielectric Nano-grating Structures

In this thesis, the dipole-surface plasmon (SP) coupling-induced dipole radiation rate enhancements over the spectral range of 400-800 nm in two air/Ag/dielectric grating nanostructures and two dipole positions based on the boundary integral-equation method are evaluated. Three kinds of SP coupling feature are identified, including plane-wave-excited surface plasmon polariton (SPP), dipole-excited SPP, and localized surface plasmon (LSP). Also, the emission enhancements of the dipole-SP coupling systems of those problem geometries on the dipole position side are calculated. The emission efficiency of a coupling system is determined by its field magnitude and phase distributions near the metal/dielectric interface. Any kind of SP coupling feature can emit either effectively or ineffectively, depending on the metal nanostructure, dipole position, and spectral location. Generally, when the Ag layer becomes thinner, the major SPP- and LSP-coupling features red-shift. The major part of emitted energy of a coupling system is released into the dipole side of the air/Ag/dielectric nanostructure.