Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 113-116). Also available for download via the World Wide Web; free to University of Oregon users.

Algorithms for analyzing laser interferometry signals were developed and adopted to the computer based processing of small displacement measurements. These methods, matrix operation approach and fixed parameters approach, are based on signal phase calculation and are able to replace complex fringe counting electronic circuits. The matrix operation provides an approach for instantaneously displaying the results. The computer fixed parameters analysis allows the laser intensity to vary arbitrarily during a measurement. Displacement caused by a piezoelectric crystal was measured. Second order polynomial curve fitting was performed. The root mean square error is found to be 0.0086 μm in this 8-bit data acquisition system. CTEs of a fused silica plate and a tube were measured by an interferometry system. Signals were analyzed by both manual chart approach and computer based fixed parameters approach. Results agree well with published data. The accuracy of the CTE measurement system was 4 μ€, one third of the reference NBS SRM 739 suggested standard deviation. Out-of-plane and in-plane displacements can be measured independently from speckle interferometry. Their resolutions are 0.3164 μm/cycle for the out-of-plane configuration and 0.224 μm/cycle for the in-plane configuration with light incident angle of 45°. Optical systems with Fast Fourier Transform data analysis showed that the minimum detectable vibration amplitudes were 0.0065 μm, 0.0038 μm, and 0.0010 μm for the out-of-plane speckle, the in-plane speckle, and Michelson interferometry systems respectively. Resonance frequency of a steel rod was found by the optical non-contact sensing system. The modulus of elasticity calculated from the resonance frequency was close to the literature data, 182 GPa vs. 200 GPa. / Graduation date: 1992

Thesis (M.S.)--University of North Texas, May, 2009. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 96-104). Also available in electronic version. Access restricted to campus users.

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

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Research Project Technical Completion Report (A-109-Ariz.) For: United States Department of the Interior, Project Dates: 1981-1983, September 1, 1983. / The Research on which this project is based was financed in part by the U.S. Department of the Interior, as authorized by the Water Research and Development Act of 1978 (P.L. 95-467) / A liquid level interferometer has been built to measure changes in water level to an accuracy of /8. A novel magnetic suspension is used to position the floating retroreflector of a laser interferometer. Direction sensing is achieved by dual optical channels phased near quadrature by means of an absorbing beamsplitter. The interferometer (laser) has been used to measure very accurately the drop in water level of a lined reservoir. The drop in water level thus provides a precise method of measuring evaporation. It was found that this drop in water level essentially ceased when the relative humidity approached very closely or equaled 100 percent during early morning calm periods. This provides a method of determination of seepage loss. In an unlined reservoir during calm periods when the relative humidity is 100 percent any remaining drop in water level is due to seepage. The laser can measure this rate.

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