At the heart of the field of photonics is the control of the reflection and transmission of light. Plasmonics looks at this problem of control of electromagnetic radiation in the context of surface plasmon polaritons (SPP). SPPs are propagating electromagnetic modes localized at the interfaces between media with positive and negative permittivities. Their excitation can accompany the enhancement of transmission, reflection, or absorption of EM radiation. There are a number of ways to excite SPPs and this work looks at several geometries and analyzes the transmission and reflection characteristics using a numerical approach based on the finite element method.<p>
The first method of excitation is by incident evanescent wave that was totally internally reflected from an earlier interface. It is shown that an evanescent wave can excite SPPs and create resonant transmisison. It is also found that high values of dissipation limit transmission and instead create resonant absorption. The second method involves the modulation of the negative permittivity of the plasma slab itself. Numerical results are compared to analytical ones and are in good agreement because harmonics of the solution above the first are negligible. An investigation of transmission through a plasma slab with a single thin diffraction grating placed nearby follows. Analytical and numerical calculations show that a single thin grating is sufficient to create transmission resonance. It is found that for large values of diffraction grating modulation parameter, higher harmonics, usually not accounted for in analytical solutions, results in discrepancies between analytical and numerical results. The next geometry considered is of a plasma layer with only part of it having modulated permittivity. The presence of modulation of only part of the plasma layer is shown to create transmission and reflection resonances. By tailoring parameters of the system, it is shown how the resonant frequencies can be shifted. The final geometry considers a copper grating beside a plasma and transmission of a radio frequency wave. Even though the copper used here in this simulation is very absorbing, there are ranges of frequencies when transmission or reflection are enhanced.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-11262010-155150 |
| Date | 21 April 2011 |
| Creators | Varady, Koloman |
| Contributors | Hirose, A., Xiao, c., Dick, R., Cheviakov, Alexei, Smolyakov, Andrei |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-11262010-155150/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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