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dc.contributor.authorBescherer-Nachtmann, Klaus
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date2013-04-23 14:08:16.33en
dc.date.accessioned2013-04-23T21:19:47Z
dc.date.available2013-04-23T21:19:47Z
dc.date.issued2013-04-23
dc.identifier.urihttp://hdl.handle.net/1974/7906
dc.descriptionThesis (Ph.D, Chemistry) -- Queen's University, 2013-04-23 14:08:16.33en
dc.description.abstractCavity ring-down spectroscopy has been used over the last twenty years as a highly sensitive absorption spectroscopic technique to measure light attenuation in gases, liquids, and solid samples. An optical cavity is used as a multi-pass cell, and the decay time of the light intensity in the cavity is measured, thereby rendering the techniques insensitive to light intensity fluctuations. Optical waveguides are used to build the optical cavities presented in this work. The geometries of such waveguides permit the use of very small liquid sample volumes while retaining the advantages of cavity ring-down spectroscopy. In this thesis cavity ring-down measurements are conducted, both, in the time domain and by measuring phase-shifts of sinusoidally modulated light, and the two methods are theoretically connected using a simple mathematical model, which is then experimentally confirmed. A new laser driver, that is compatible with high powered diode lasers, has to be designed to be able to switch from time domain to frequency domain measurements. A sample path length enhancement within the optical cavity is explored with the use of liquid core waveguides. The setup was optimised with respect to the matrix liquid, the geometrical matching of waveguide geometries, and the shape of liquid core waveguide ends. Additionally, a new technique of producing concave lenses at fibre ends has been developed and the output of a general fibre lens is simulated. Finally, liquid core waveguides are incorporated into a fibre-loop ring-down spectroscopy setup to measure the attenuation of two model dyes in a sample volume of <1 µL. The setup is characterized by measuring concentrations of Allura Red AC and Congo Red from 1 µM to a limit of detection of 5 nM. The performance of the setup is compared to other absorption techniques measuring liquid samples.en_US
dc.languageenen
dc.language.isoenen_US
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectRing-Cavityen_US
dc.subjectLiquid Core Waveguideen_US
dc.subjectMultimode Fiberen_US
dc.subjectConcave Lensen_US
dc.subjectMultiexponentialen_US
dc.subjectCongo Reden_US
dc.subjectAllura Reden_US
dc.subjectFiber Lensen_US
dc.subjectFiber Loopen_US
dc.subjectGlass Capillaryen_US
dc.subjectDecay Lengthen_US
dc.subjectAbsorption Spectroscopyen_US
dc.subjectOptical Fiberen_US
dc.subjectPhase Shiften_US
dc.subjectDiode Laseren_US
dc.subjectVariable-Frequency Phaseen_US
dc.subjectCavity Enhanced Absorption Spectroscopyen_US
dc.subjectResonatorsen_US
dc.subjectLifetimeen_US
dc.subjectAmplitude Modulationen_US
dc.subjectKineticsen_US
dc.subjectLaser Driveren_US
dc.subjectCavity Ring-Downen_US
dc.subjectOptical Attenuationen_US
dc.titleFibre-Loop Ring-Down Spectroscopy Using Liquid Core Waveguidesen_US
dc.typethesisen_US
dc.description.degreePh.Den
dc.contributor.supervisorLoock, Hans-Peteren
dc.contributor.departmentChemistryen


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