Chalcogenide glasses have a wide transmission window which can extend from the far-visible to the mid-infrared (IR) range. They have very high optical nonlinearity compared to silica glasses, low phonon energies, photosensitive properties and can be doped with rare earth elements. Chalcogenide glasses have attracted the research for different optical applications such as optical imaging, integrated optics and all-optical switching. In this Project, chalcogenide glasses were Radio-Frequency (RF) sputtered to form two Bragg mirror structures both with a stop-bands in the telecommunications and near-infrared and each comprised of alternating layers of two chalcogenide glass pairs: AS4oSe601Ge17As!sSe65 and GelsAs1SSel7 Te53! Ge17As18Se65 (atomic %). Two alternative techniques: hot embossing and Inductively Coupled Plasma (ICP) etching were used to fabricate rib waveguides in RF sputtered As40Se60 chalcogenide glass thin films on Gel7AslSSe6S chalcogenide glass substrates. Previous work on hot embossing of thermally evaporated thin films has produced rib waveguides with a reported optical loss down to 2.9 dB cm-1. In this work, hot embossing was used to fabricate successfully rib waveguides with optical loss < 0.78 dB cm•1 for the quasi-TE mode and < 0.81 dB cm-1 for the quasi-TM mode. ICP etching was also successfully used to fabricate rib waveguides in similar sputtered films with optical loss < 1.05 dB cm-l for the quasi-TE mode and < 1.12 dB cm-l for the quasi-TM mode. Measurements of optical properties such as linear absorption coefficient (a), linear refractive index (no), bandgap energy (Eg), nonlinear refractive index (n2) and nonlinear absorption coefficient (β2) were carried out on chalcogenide glass samples with compositions varied systematically within the ternary systems As-S-Se and As-Se-Te. These fundamental measurements are important in the further development of any chalcogenide based optical component.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:594816 |
| Date | January 2013 |
| Creators | Abdel-Moneim, Nabil Sayed Mohamed |
| Publisher | University of Nottingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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