The interaction of electrons and phonons with the properties of semiconducting crystals continues to be a fascinating and highly fruitful field of study. This dissertation addresses two research problems under the general heading of electron and phonon effects on the optical properties of indirect gap semiconductors.
The first problem concerns nonlinear (multi-photon) absorption in germanium crystals, a topic of interest for the telecommunications industry as well as to the basic scientist. Using a combination of infrared transmittance experiments and numerical analysis, the two- and three-photon absorption coefficients β and γ for germanium have been evaluated over the range of wavelengths from 2.8 µm to 5.2 μm. The ratios of the coefficients across the direct/indirect gap transitions and between the two-and three-photon cases, which are less susceptible to experimental uncertainties than the absolute coefficients, have also been determined. Comparison with theoretical studies shows excellent agreement.
The second problem addresses the optical characteristics of ion-bombarded diamond crystals, which is a swiftly developing field due to diamonds current status as the material of choice for hosting photonic and quantum information devices. The ultrafast optical technique known as coherent acoustic phonon interferometry has been applied to He ion irradiated diamond crystals for the purpose of determining the optical modification induced by the implantation damage. The experimental results provide information about the variation at in the complex refractive indices of the implanted specimens as well as the variation in the photoelastic tensor. A simple phenomenological model quantitatively describing the damage-induced optical modification has been developed which accurately predicts the experimental observations, and may prove to be a useful tool for quantum device design.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-03192013-124229 |
| Date | 27 March 2013 |
| Creators | Gregory, Justin Mark |
| Contributors | Norman Tolk, Jim Davidson, Leonard Feldman, Timothy Hanusa, Sokrates Pantelides, Ronald Schrimpf |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-03192013-124229/ |
| Rights | restrictone, 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 Vanderbilt University 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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