Nonlinear optical phenomena in fluoride glass and hybrid fibres

  • Stefan Fischbach

Student thesis: Doctoral ThesisPhD


This thesis investigates nonlinear optical phenomena in non-silica fibres,in a first part utilising a fluoride fibre, followed by the exploration of hybridfibres with an organic single crystal inside a fibre capillary. The uniqueproperties of 55ZrF4, 18BaF2, 6LaF3, 4AlF3, 17NaF (ZBLAN) glass allow thecreation of optical fibres with a highly extended transmission window on thelonger wavelength side. We investigated the properties of ZBLAN fibres inorder to optimise supercontinuum (SC) generation in a ZBLAN fibre pumpedby an optic parametric amplifier. To study applications of the ZBLAN SCwe integrated the SC into a pump-probe setup, being used as a near-infraredbroadband probe source. We have carried out proof-of-principle measurementson an organic copolymer thin-film, showing the possibility of utilising aZBLAN SC, allowing to extend the usability of broadband sources to the nearandmid-infrared, while simplifying the usage of the setup.The second part of this thesis explores the possibilities of hybrid fibres byusing a hollow-core silica capillary with an organic single-crystal inside. Wehave developed and optimised a method to grow an organic semiconductingcrystal inside a hollow core capillary based on the Bridgman-technique. Wecould demonstrate the filling of the inner capillary for diameters down to 1 mand with different materials based on the anthracene structure, opening uppossibilities for various hybrid fibres. The quality of the single-crystals wasevaluated by micro-Raman and X-ray diffraction measurements. We couldaccess nonlinear properties of the crystal by coupling light with an energylower than the band-gap into the fibre. Stimulated by two-photon absorptionphoto-luminescence from the fibre core was observed for the hybrid fibre. Theresults obtained for the hybrid fibres gives rise to a vast amount of possibilitiesfor different hybrid fibres with tailored optical properties of organic materialsand their optimisation in the guiding of light.
Date of Award25 May 2017
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorEnrico Da Como (Supervisor)

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