Show simple item record

Files in this item


Item metadata

dc.contributor.advisorDholakia, Kishan
dc.contributor.authorShah, Anjali
dc.coverage.spatialxi, 187 leavesen
dc.description.abstractSemiconductor diode lasers are successful tools in atomic spectroscopy. They are routinely used in frequency conversion applications to develop devices that access regions of the spectrum not directly available. This thesis describes the practical application of novel violet diode laser systems and their possible inclusion in spectroscopic systems. The design, assembly and successful operation of a doubly resonant optical parametric oscillator is described. There is discussion of the spectral behaviour of the device and the potential for pumping with a violet diode laser. Methods to adapt the output from the solitary diode devices are demonstrated with the use of microlensed diode lasers and extended cavity configurations. Details of the current tuning, linewidth and smooth tuning characteristics of a number of the lasers used are given. A commercial violet diode laser is used within an extended cavity to measure the hyperfine structure of atomic indium from a hollow cathode galvatron source at room temperature. Stabilisation of the diode laser to a line from the indium spectrum is attempted. The remainder of the thesis is concerned with the development of techniques to deliver clearer and more precise spectral information about trace species. Microlensed red and violet diode lasers are used to generate light at 254nm via sum frequency generation for the direct detection and modulation spectroscopy of mercury vapour, with microlensed lasers with modulation allowing more accurate discrimination between spectral features than direct absorption measurements. In addition Raman tweezers modulation spectroscopy is undertaken to investigate polymer microspheres and biological cell samples where the use of the modulation technique demonstrated improvements in the acquisition time and clarity of spectra through increased signal to noise and rejection of background fluorescence effects. A comparison between the direct and modulation techniques for all the systems indicates the greater sensitivity of the modulation technique.en
dc.format.extent12011820 bytes
dc.publisherUniversity of St Andrews
dc.rightsCreative Commons Attribution-NonCommercial-NoDerivs 2.5 Generic
dc.subjectSemiconductor diode lasersen
dc.subjectAtomic spectroscopyen
dc.subjectViolet diode laser systemsen
dc.subjectSpectroscopic systemsen
dc.subject.lcshNonlinear optics
dc.subject.lcshAtomic spectroscopy
dc.titleExternal cavity diode lasers and non-linear optical frequency conversion in spectroscopic applicationsen
dc.type.qualificationnamePhD Doctor of Philosophyen
dc.publisher.institutionThe University of St Andrewsen

The following licence files are associated with this item:

  • Creative Commons

This item appears in the following Collection(s)

Show simple item record

Creative Commons Attribution-NonCommercial-NoDerivs 2.5 Generic
Except where otherwise noted within the work, this item's licence for re-use is described as Creative Commons Attribution-NonCommercial-NoDerivs 2.5 Generic