Optical and Plasmonic Properties of Metallic Tip /Surface Junctions

Reducing symmetry of plasmonic nanostructures allows more in-depth engineering for plasmonic systems to support a range of optical phenomena prohibited by traditional symmetric systems. Symmetry reduction allows for nanoscale control of the near-field and far-field electric and magnetic resonances at optical frequencies. Introducing a nanopraticle or a tip to an infinite metallic surface breaks the continuity of the surface allowing coupling with light. This leads to remarkable nearfield focusing and enhancement at optical resonances through the gap between the metallic nanoparticle/tip and the metallic surface. In this work, we examine twodimensional and three-dimensional variations of reduced symmetry systems and we present a fully retarded electromagnetic study for the plasmon interaction through the tip/surface junction. A simple methodology is introduced for efficient, fast, and accurate simulation for such systems using the both Finite-Difference Time-Domain and Finite-Element methods. The proposed methods are used to predict the response of practical systems and the results are compared with previously reported experimental and electrostatic-theoretical results and a remarkable agreement is reported. A full study for the tip over film system is established to provide optimized geometries for Tip Enhanced Raman Spectroscopy (TERS) applications.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Engineering

Grantor

Rice University

Year dc:date.issued

2011

Author dc:creator

• Ali, Tamer Ashour

Advisor dc:contributor.advisor

• Nordlander, Peter J.

• Electrical Engineering

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/64368

OAI identifier oai:identifier

oai:repository.rice.edu:1911/64368