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Methods for analysis and optimization of volume holographic recording are presented for two main groups of applications. In the first group of applications (mainly storage systems), the designs and the techniques of volume holography are well known and the main optimization effort is finding the proper material to store the holograms. One of the results of this research is complete global optimization of dynamic range and sensitivity in two-center recording that is the best technique for persistent rewritable storage. For this purpose, a complete theoretical analysis as well as experimental demonstration is presented. Also, other effects and processes such as electron tunneling and recording at high temperature are considered for possible improvement of the dynamic range of the material. For the second group of applications (mainly holographic optical elements), the focus of this research is on analysis and optimization of the design of the volume holograms in contrast to material optimization. A new method (multi-grating method) is developed for the analysis of an arbitrary hologram that is based on the representation of the hologram as the superposition of several plane wave gratings. Based on this method, a new class of optical devices that integrates the functionalities of different optical elements into a simple volume hologram is introduced and analyzed. As a result, very compact, low cost, and easy to use devices such as portable spectrometers can be made with particular applications in biological and environmental sensing.

This thesis presents instrumentation with which to measure the abundance of neutral hydrogen gas in the Universe. Measuring where the Universe’s hydrogen is, and tracing how its distribution evolves with time, holds the key to understanding how galaxies evolve, the nature of dark energy, and how the first cosmic structures formed. In particular, this thesis looks at instrumentation for 21-cm intensity mapping telescopes. In 21-cm intensity mapping, the collective emission of many galaxies is measured, without individual detections. This technique promises to allow detection of the baryonic acoustic oscillation peaks in the power spectrum of the Universe’s matter distribution. Such a detection would increase constraints on cosmological parameters. There are two main approaches to designing a 21-cm intensity mapping instruments: using a filled aperture instrument such as a single-dish telescope, or using a sparse aperture instrument such as an interferometric array of dipoles. This thesis investigates analogue components for a sparse aperture instrument operating at 1.0-1.5 GHz. As part of this work, a 16-element sparse aperture array was designed and constructed. To test the array’s performance, field testing was conducted; the results of which are presented here. In addition to this, I have designed a new digital spectrometer for redshifted hydrogen line science, named HISPEC. A copy of this spectrometer has been installed on the Parkes 64 m telescope, as a digital signal processor for the 21-cm multibeam receiver. HISPEC has increased instantaneous bandwidth, higher interchannel isolation, and improved quantization efficiency as compared to the existing backend, MBCORR. The HISPEC equipped multibeam receiver is an ideal instrument for 21-cm intensity mapping at redshifts z<0.2.

The investigations described within this dissertation foretell the imminent revolution in optical analytical spectroscopy and conclusively demonstrate superior qualitative and quantitative analysis performance of a new system for atomic spectroscopy as compared to present, state-of-the-art instrumentation. The advent of a new class of multichannel detectors, the silicon charge transfer devices (CTDs) is shown to significantly impact ultraviolet, visible, and near-infrared analytical spectroscopy. An overview of the operation, characteristics, and performance of CTDs is presented including the results of the characteristics of a CTD detector system developed during these investigations. Theoretical comparisons of the performance obtainable in spectroscopic systems employing CTD detectors versus conventional detectors, including equations identifying the factors limiting sensitivity, demonstrate that CTDs offer superior performance. The second part of this dissertation describes the application of a particular CTD, the charge injection device (CID), to a very challenging spectroscopic problem, as far as light detection is concerned, simultaneous multielement analytical atomic emission spectroscopy. This widely employed technique for qualitative and quantitative elemental analysis requires sensitive and wide dynamic range detection of a large number of spectral resolution elements. This research resulted in the development of a novel echelle spectrometer employing a CID detector which has been demonstrated to be capable of solving many of the problems currently encountered in analytical atomic spectroscopy. The system achieves superior sample throughput rates, flexibility, accuracy and precision as compared to sequential spectrometers employing a single detector and to polychromators employing relatively few fixed detectors. The research included the development of a unique method of operating the CID, which is used to cope with the very wide dynamic range signals encountered in atomic spectroscopy, and has resulted in a spectroscopic instrument able to qualify simultaneously major and trace components of extremely complex samples with greater sensitivity and accuracy than possible with conventional instrumentation. New, very flexible, and extremely rapid methods of qualitative analysis have also been developed which virtually eliminate the possibility of spectral line misassignment. The atomic emission spectroscopic system is applicable in a variety of analytical areas as diversified as high sensitivity detection of near infrared spectral lines and element-specific detection of chromatographic eluents.

No description available.

Thesis (Ph. D.)--Washington State University, December 2007. / Includes bibliographical references.

The production and distribution of counterfeit drugs is a critical health problem that plagues nations worldwide. The presence of counterfeit antimalarials has become especially worrying, as these drugs are most often needed by those living in nations whose resources to verify the medicine supply are lacking. Rapid analysis methods used for screening large quantities of poor quality antimalarials are critical in the battle to protect those in less developed regions of the world. Simple, cost effective analysis methods that can be used in the field must be developed so those whose governments cannot afford to maintain medicine regulatory agencies can still have faith in their medicinal supply. A very powerful screening method, Direct Analysis in Real Time Mass Spectrometry (DART-MS) has been used to investigate thousands of poor quality medicines. This method, however, is known to fragment molecules more readily than commonly used, 'softer' ionization methods, such as electrospray ionization. Excess fragmentation in 'harder' ionization sources is due to deposition of additional internal energy to the ionized molecules. This internal energy deposition can be measured, so the analyst can be knowledgeable as to what to expect when examining unknowns using this recently developed ionization source. Quantitation of the active pharmaceutical ingredient (API) in pharmaceuticals is crucial to the determination of what class a poor quality medicine fits into. Because poor quality drugs can be of different types, it is important to accurately classify them, in hopes of improving the supply of medicines available to those in less developed regions of the world. High performance liquid chromatography (HPLC) is most commonly used to quantify the active pharmaceutical ingredient in poor quality medicines, however, this method is time consuming, preventing its use in high throughput settings. During the course of my research, hundreds of poor quality pharmaceuticals were analyzed using DART-MS. The active pharmaceutical ingredient was detected during the rapid screening for many of these drugs, however, a more in depth analysis would often reveal less than the expected quantity of active ingredient. A rapid non-chromatographic quantitation method was developed using a mass spectrometer as the detector. This method allows for both quantitative and qualitative information regarding a specific sample to be obtained simultaneously, saving the analyst time and resources. Utilizing this non- chromatographic mass spectrometric method, degradation products have been identified, thus increasing our ability to classify drugs into their respective divisions.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.