| The fiber-optic gyroscope is relatively new, and potentially important, type of rotation sensor. It consists largely of a loop interferometer which, for the purpose of increasing the rotation sensitivity, includes a coiled single-mode fiber on the order of 1 km in length. Unfortunately, the use of the fiber in the interferometer causes, along with the benefits, measurement errors. Since the fiber parameters are sensitive to the environment, these errors tend to vary in time, and contribute drift and noise to the signal. Furthermore, nonideal components, often acting together with spurious fiber effects, cause additional time-varying errors. Much of the research on this subject to date has been involved in identifying the error sources, and in designing the system to reduce their effect on the signal. This dissertation presents contributions which, in combination with many others, have lead to fiber gyroscopes with inertial-navigations-grade performance at low rotation rates.; To provide a perspective, an overview of fiber-optic gyroscopes is presented. This includes the fundamental considerations for the design of a sensitive system, a discussion of parasitic effects arising from the fiber, and a look at the state-of-the-art technology and performance.; In light of this we present a fiber gyroscope which makes use of single-mode fiber-optic components developed in part for this application. A major advantage of this approach is the stable low-loss low-reflection interface between the components and the fiber loop. Furthermore, the high component quality provides the possibility for the highest ultimate rotation sensitivity. With such a system, we have demonstrated short-term sensitivity three orders of magnitude below heart rate, and stability over periods of hours of better than two orders of magnitude below earth rate. This compares favorably with the performance of ring laser gyroscopes.; Finally, we consider the optical Kerr effect in the fiber which causes a rotation rate error that is critically dependent on the optical power difference between the counterpropagating waves. This places unreasonable restrictions on a variety of system parameters, including the splitting ratio of the loop directional coupler. We show that a time-varying source power can be used to reduce the restrictions, and demonstrate a reduction of the Kerr-induced rotation rate error of greater than two orders of magnitude. |
