الفهرس 
RLG SYSTEM REVIEWOnly 14 pages are availabe for public view
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Abstract
ABSTRACT
This thesis aims at improving our understanding of one of the main topologies of optical gyroscopes, the fiber based ring laser gyroscope. This type of fiber rotation sensors is considered one of the recent configurations in the past decade that expected to present a good alternative to the other available optical gyros such as He-Ne RLG and FOG in the industrial and commercial market due to its low cost, its integration capability and ease for fabrication and maintenance. Since this configuration still has some performance limitations such as limited dynamic range and noise performance, due to multiple longitudinal modes’ MLM operation, and increased lock-in effect which limits the system’s sensitivity at low rotation rates, we intend to provide a theo-retical and experimental study of lock-in phenomena in F-RLG system and propose a practical solution for it based on optical MEMS technology and as well, introducing a practical solution of the MLM operation.
To this end, A MEMS based optical phase modulator based on corner cube micro-mirror is presented and proposed as a solution for the lock-in removal in F-RLG instead of the conventional mechanical dithering techniques, since the MEMS Phase modulator PM is less expensive, has lower weight and is more compatible with fiber systems. The designed device is fabricated using the deep Reactive Ion Etching DRIE technology, aligned to and integrated with optical fibers in a single package. The Phase modulation as well as frequency modulation of the ring laser using the fabricat-ed device is demonstrated experimentally in the lab. A Numerical model is also devel-oped for the accurate simulation of the ring laser demonstrating the lock-in phenome-na in F-RLG. The model is based on the solution of the rate laser equations for both the field amplitudes and phase. It allows the study of the elimination of the lock- in using the MEMS PM. The F-RLG system was experimentally characterized with giving more focus on the lock-in effect. However, the experimental of lock-in elimina-tion using the developed MEMS PM was not completed due to unavailability of lensed fibers with the designed specs to achieve the required performance. A new scheme for single longitudinal mode operation of FRL in bi-directional sense was also demonstrated experimentally as a step in developing SLM F-RLG to avoid the prob-lems of MLM operation of F-RLG.