Plasmonics: Numerical Methods and Device Applications

Citation

Sweatlock, Luke A. (2008) Plasmonics: Numerical Methods and Device Applications. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/8GPE-SB31. https://resolver.caltech.edu/CaltechETD:etd-06112008-051943

Abstract

Plasmonics is a rapidly evolving subfield of nanophotonics that deals with the interaction of light with surface plasmons, which are the collective charge oscillations that occur at the interface between conductive and dielectric materials. Plasmonics meet a demand for optical interconnects which are small enough to coexist with nanoscale electronic circuits. Emerging technologies include very small, low-power active devices such as electrooptic or all-optical modulators. Passive plasmonic devices, or "optical antennas", are being used to enhance the performance of emitters and detectors, and to harvest sunlight for photovoltaics. This manuscript focuses on the process of developing novel plasmonic devices from concept to prototype, with specific emphasis on synthesizing data from numerical simulation and from empirical characterization into an accurate, predictive understanding of nanoscale optical phenomena.

The first part of the thesis outlines the development of numerical methods. In the case of resonant nanostructures such as small metal particles, the principal technique employed is impulse excitation ringdown spectroscopy. This method allows the critical advantage of generating broadband spectra from a single time-domain simulation. For analysis of plasmonic waveguides, Fourier-space analysis is used to reveal the dispersion properties of supported modes, and to perform filtering in the wavevector domain or "k-space". The remainder of the thesis deals with the design and characterization of plasmonic devices, with the broad and general goal of creating a significant impact in the fields of optoelectronics and photovoltaics.

Thesis Files