This dissertation presents both detailed experimental and extensive theoretical studies of optical wavemixing in nonlinear absorptive Kerr media. Non-degenerate two wave mixing (NDTWM) is a simple and powerful technique widely used to study the nonlinear refractive index and the grating decay time. It is unique due to its ability to separate the phase and the absorptive grating contributions. The work included in this thesis has evolved from trying to explain the unexplained results on the symmetric component of the NDTWM gain reported as "anomalous" behavior in ruby. We note that all previous theories for NDTWM have taken the approximation that the strong pump beam intensity was constant. In this approximation, the origin of unsymmetry in energy exchange between the two interacting beams was due only to the absorption grating of the weak probe beam. / We have shown both experimentally and theoretically that the contribution of the absorption grating can be neglected but not the nonlinear bias absorption--just opposite to what had been common practice. Our approach also accounts for a range of inconsistencies related to intensity dependence of both the NDTWM gain and ratio of the imaginary to the real part of the nonlinear refractive index. Weakening the probe beam, earlier believed to improve accuracy of the approximation of the constant pump beam, actually destroys the symmetry of the energy exchange between the beams, enhancing the weak probe beam at the expense of the pump beam due to nonlinear absorption. / This same two-beam coupling analysis has also been applied to interpret non-degenerate four wave mixing. Amplification of the phase conjugate signal is thus obtained. The spectral response in the frequency domain results in a tunable notch filter which can be controlled by the incident intensities of the pump beams.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.34457 |
| Date | January 1997 |
| Creators | Skirtach, Andrei G. |
| Contributors | Simkin, David J. (advisor) |
| Publisher | McGill University |
| 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 | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001565103, proquestno: NQ30388, Theses scanned by UMI/ProQuest. |
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