Fibre gratings in novel optical fibres for applications in sensing

  • Helen L. Dobb

    Student thesis: Doctoral ThesisDoctor of Philosophy


    This thesis presents the fabrication of fibre gratings in novel optical fibres for sensing applications. Long period gratings have been inscribed into photonic crystal fibre using the electric-arc technique. The resulting sensing characteristics were found to depend on the air-hole geometry of the particular fibre. This provides the potential of designing a fibre to have enhanced sensitivity to a particular measure and whilst removing unwanted cross sensitivities. Fibre Bragg gratings have been fabricated in a variety of polymer optical fibres, including microstructured polymer optical fibre, using a continuous wave helium cadmium laser. The thermal response of the gratings have been characterised and found to have enhanced sensitivity compared to fibre Bragg gratings in silica optical fibre. The increased sensitivity has been harnessed to achieve a grating based device in single mode step index polymer optical fibre by fabricating an electrically tunable fibre Bragg grating. This was accomplished by coating the grating region in a thin layer of copper, which upon application of a direct current, causes a temperature induced Bragg wavelength shift.
    Date of Award2007
    Original languageEnglish
    SupervisorDavid Webb (Supervisor) & Kyriacos Kalli (Supervisor)


    • fibre gratings
    • sensing application
    • photonic crystal fibre
    • electric-arc technique

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