We describe our investigations into photochemical and micro-structural characteristics of sol-gel derived silica-methacrylate composites (SAC). Upon irradiation with UV light, thin SAC films undergo spatially localised increases of the index of refraction, a macroscopic property that has been used in the photo-lithography of passive integrated optics devices. Our spectroscopic studies indicate that UV initiated free-radical polymerisation of methacrylate substituents trigger further growth and densification of the silica host. This advances our molecular level understanding of photo-reactions in hybrid organo-silica networks. / We examine laser-initiated organic chain growth in SAC planar waveguides. Optical modes initiate polymerisation of methacrylate substituents along the propagation path. In turn, the nascent reaction medium presents a non-uniform refractive index profile to the guided laser beam. Spatially localised and intensity-dependent refractive index changes create a lens-like profile in the medium. As a result, the beam self-focuses along its propagation axis without diffraction. / We describe oriented organic chain growth in the nonlinear optical and highly anisotropic reaction field provided by a linearly polarised, self-focusing laser beam. A self-focusing laser beam induces an anisotropy in the refractive index profile of SAC waveguides. We characterise laser-induced birefringence in the hybrid network through polarised waveguide Raman spectroscopy and optical birefringence measurements. / Long-range periodic self-organisation in sol-gel derived silica acrylate composites formed in the absence of external templates was observed for the first time. Significantly, the periodicity associated with this structure is approximately 200 nm, approaching the optical wavelength regime.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.38093 |
| Date | January 2000 |
| Creators | Saravanamuttu, Kalaichelvi. |
| Contributors | Andrews, M. P. (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: 001844943, proquestno: NQ75677, Theses scanned by UMI/ProQuest. |
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