Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph. D.)--University of London, 1931. / "Bibliography and list of patents": p. 160-161.

Thesis (M.S.)--University of Wisconsin--Madison, 1962. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 32).

D.Ing. (Electrical & Electronic Engineering) / Please refer to full text to view abstract

No description available.

This thesis presents a study of a 1.6 metre square, helium-neon based ring laser gyroscope (denoted PR-1). This device is mounted on one of the internal walls of a high rise building. After optimisation a cavity Q of 2.9x10¹¹ and a sensitivity to rotation of approximately 10⁻³ of the background Earth bias was obtained. A detailed investigation of the single mode operating regime and multi-mode thresholds was undertaken and could be well accounted for with a simple model of the gain curves. A key feature of the operation of PR-1 is persistent longitudinal mode hopping. It is shown that by running the laser at selective high powers, one obtains CW mode locked operation thereby negating the influence of mode hopping and allowing for long time data acquisition. PR-1 was used to demonstrate oscillation of the Rutherford building on its second fundamental mode during an earthquake. In a separate investigation, a range of supermirrors were studied to determine the optimum configuration in a 4 by 4 metre ring laser. The set with the highest finesse prevailed despite the comparatively low light levels on the photo detectors. The geometric stability of the lasers was not found to be a significant factor.

This thesis presents a study of a 1.6 metre square, helium-neon based ring laser gyroscope (denoted PR-1). This device is mounted on one of the internal walls of a high rise building. After optimisation a cavity Q of 2.9x10¹¹ and a sensitivity to rotation of approximately 10⁻³ of the background Earth bias was obtained. A detailed investigation of the single mode operating regime and multi-mode thresholds was undertaken and could be well accounted for with a simple model of the gain curves. A key feature of the operation of PR-1 is persistent longitudinal mode hopping. It is shown that by running the laser at selective high powers, one obtains CW mode locked operation thereby negating the influence of mode hopping and allowing for long time data acquisition. PR-1 was used to demonstrate oscillation of the Rutherford building on its second fundamental mode during an earthquake. In a separate investigation, a range of supermirrors were studied to determine the optimum configuration in a 4 by 4 metre ring laser. The set with the highest finesse prevailed despite the comparatively low light levels on the photo detectors. The geometric stability of the lasers was not found to be a significant factor.

MEMS gyroscopes are electromechanical devices that measure rate or angle of rotation. They are one of the fastest growing segments of the microsensor market. Advances in microfabrication technologies have enabled the implementation of chip scale monolithic gyroscopes (MEMS gyroscopes) with very small form factor that are lightweight and consume little power. Over the past decade, significant amount of research have been directed towards the development of high performance and very small size MEMS gyroscopes for applications in consumer electronics such as smart phones. In this dissertation, high aspect-ratio hemispherical shell structure with continuously curved surface is utilized as the high Q resonator. Being an axial symmetric structure, the 3D hemispherical shell is able to achieve low frequency (3 ~ 5 kHz) within 2 mm X 2mm die area. Detailed analysis on energy dissipation also shows its potential to achieve ultra-high quality factor with the selection of high Q material and proper design of support structure. This dissertation presents, for the first time, the analysis, design, fabrication and characterization of a micro-hemispherical resonating gyroscope (μHRG) that has the potential to be used as a whole angle micro-gyroscope. A three-dimensional high aspect-ratio poly- and single crystalline silicon (3D HARPSS) process is developed to fabricate free-standing, stem-supported hemispherical shell with self-aligned deep electrodes for driving, sensing and quadrature control of the gyroscope. This monolithic process consists of seven lithography steps and combines 3D micro-structure with curved surfaces with the HARPSS process to create capacitive electrodes with arbitrary gaps around the micro-hemispherical shell resonator (μHSR). Polysilicon is utilized as the structural material due to its isotropic mechanical properties and the potential of achieving high quality factor. The fabrication is demonstrated successfully by prototypes of polysilicon μHRG with diameter of 1.2 mm and thickness of 700 nm. Frequency response and gyro operation are electronically measured using the integrated electrodes. Quality factor of 8,500 is measured with frequency mismatch of 105 Hz. Electronic mode matching and alignment are successfully performed by applying tuning voltages and quadrature nulling voltages. An open loop rate sensitivity scale factor of 4.42 mV/°/s was measured. Design and process optimization of the support structure improved the quality factor to 40,000. Further improvement of quality factor will enable the demonstration of high performance RIG using polysilicon μHRG.

by Tong Shiu Sing Dominic. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 242-245). / Acknowledgements --- p.iv / Abstract --- p.v / Chapter I --- Introduction --- p.1 / Chapter 1.1 --- A general review of the theory --- p.1 / Chapter 1.2 --- An outline of this thesis --- p.6 / Chapter II --- Dispersion surfaces of cold magnetoplasmas --- p.9 / Chapter 2.1 --- Meaning of dispersion surface and wavevector surface --- p.9 / Chapter 2.2 --- Dispersion surfaces of a two component electron-ion magnetoplasma --- p.13 / Chapter 2.3 --- Dispersion surfaces of a three component electron-ion-positron magnetoplasma --- p.35 / Chapter 2.4 --- Dispersion surfaces of a three component electron-ions magnetoplasma --- p.50 / Chapter 2.5 --- Doppler shifted wavevector surfaces (DWS) --- p.61 / Chapter A. --- Examples of DWS in an isotropic cold plasma --- p.61 / Chapter B. --- Examples of DWS in a cold magnetoplasma --- p.62 / Chapter 2.6 --- Dispersive surfaces of a moving magnetoplasma --- p.63 / Chapter III --- Evaluation of far field caused by a moving source --- p.72 / Chapter 3.1 --- Maxwell's equations and constitutive relations --- p.72 / Chapter 3.2 --- Calculation of far field by Lai and Chan's method --- p.75 / Chapter 3.3 --- Radiation energy flow --- p.85 / Chapter IV --- Controversy of Lai and Chan's method --- p.94 / Chapter 4.1 --- Origin of the controversy --- p.94 / Chapter 4.2 --- Evaluating the far field by the method of other authors --- p.97 / Chapter 4.3 --- "Comparsion of the fields found by Lai, Chan and other authors" --- p.100 / Chapter A. --- Comparing the far fields in an uniaxial non-dispersive medium --- p.101 / Chapter B. --- Comparing the far fields in an isotropic cold plasma --- p.104 / Chapter 4.4 --- Some remarks on the method of stationary phase --- p.109 / Chapter V --- Gyro-radiation in a cold magnetoplasma --- p.113 / Chapter 5.1 --- Introduction --- p.113 / Chapter 5.2 --- Radiation energy flux caused by a moving dipole in a magnetoplasma --- p.115 / Chapter 5.3 --- Radiation energy flux caused by a gyrating electron in a magnetoplasma --- p.135 / Chapter VI --- The ratio of emitted to received power in a magnetoplasma --- p.186 / Chapter 6.1 --- Introduction --- p.186 / Chapter 6.2 --- Methol of calculating the ratio of emitted to received power --- p.187 / Chapter 6.3 --- Numerical examples of the power ratio in a magnetoplasma --- p.191 / Chapter VII --- Evaluation of far field in a moving medium --- p.199 / Chapter 7.1 --- Introduction --- p.199 / Chapter 7.2 --- Far field expression in a moving medium --- p.200 / Chapter 7.3 --- Relation between Lai and Chan's far field and the far field in a moving medium --- p.206 / Chapter VIII --- Radiation in some moving media --- p.216 / Chapter 8.1 --- Introduction --- p.216 / Chapter 8.2 --- Radiation in a moving isotropic non- dispersive medium --- p.216 / Chapter 8.3 --- Radiation in a moving isotropic cold plasma --- p.223 / Chapter 8.4 --- Radiation in a moving cold magnetoplasma --- p.226 / Chapter IX --- Conclusions --- p.232 / Appendix A --- p.235 / Appendix B --- p.238 / Appendix C --- p.241 / References --- p.242

Thesis (M.S. in Astronautical Engineering)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Roberto Cristi, Brij Agrawal. Includes bibliographical references (p. 53). Also available online.