| Optical waveguides are used extensively for data communications and optical sensing applications. Plasmonic waveguides, which transport electromagnetic waves along metallic surfaces via the surface plasmon-polariton (SPP), offer access to modes characterized by highly localized fields that are extremely sensitive to their surroundings. These properties are ideal for the applications mentioned. SPPs, however, suffer significant attenuation as they propagate, a fact which limits their usefulness. This thesis investigates the propagation of SPPs along metal films and strips in layered dielectric backgrounds as structures capable of supporting low loss SPP modes. The guided modes are investigated in one and two dimensional cases by analytical and numerical methods respectively. Calculations show that the attenuation of the SPP can be reduced significantly, over a wide range of wavelengths. The reduction in attenuation is compared with degree of energy localization, which is also an issue of concern. |
