Document Type

Theses, Ph.D


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence


Electrical and electronic engineering

Publication Details

Thesis submitted for the Degree of Doctor of Philosophy to Technological University Dublin, May 2015.


Guiding light at the nanoscale shows significant importance for the next generation on-chip information technology, as it could enable dramatic miniaturization of integrated photonic circuits (IPCs). Conventional dielectric photonic devices cannot be used to realize highly IPCs due to the diffraction limit. A promising solution to this challenge is to explore surface plasmon polaritons (SPPs) based waveguides, which can guide light beyond the diffraction limit. Therefore, a deeper understanding of SPPs based waveguides is developed in this thesis, as a basis for the design of novel plasmonic devices which are essential for building IPCs. However inherent ohmic loss in plasmonic waveguide is very large and the loss will be further increased by reducing the size of IPCs, which limited their applications. Thus the critical challenge for SPPs waveguide is how to increase the propagation length, in the meanwhile maintain a tight mode confinement. Thus several novel plasmonic waveguides are developed to address the challenge of improving the propagation length while maintaining very tight mode confinement. SPPs are exceptionally sensitive to the dielectric properties near the metal surface because of their highly localized fields at the metal surface, offering substantial potential for effective sensing applications. Therefore the application for plasmonic sensing is also explored in the thesis. Several new plasmonic biosensors are designed to achieve a high sensitivity and simultaneous measurements of multiple parameters.