9312674 Wanser We plan to investigate, experimentally and theoretically, the fundamental performance limits of fiber optic interferometers and methods for improving fiber optic gyroscopes and sensors employing nonlinear phase transducers. Phase noise in Mach Zehnder, and polarization fade free Michelson interferometers will be measured at 300 K and 77 K, and compared to a recent theory. The phase noise in novel polarization stabilized fiber optic ring resonator interferometers will be investigated both experimentally and theoretically. The minimum detectable phase shift of a novel double pass ring resonator configuration for comparable (short) length interferometers. Sources of noise, residual signals and offset in nonlinear magnetostrictive transducers will be investigated experimentally and theoretically. Novel methods of transducer bias, dithering, and interferometer signal demodulation and feedback stabilization will be employed. A nonlinear driven parametric oscillator model of the magnetic transducer will be developed to study the generation of subharmonics and nonlinear noise, and the role played by nonlinearity in generation of residual signals. The final area to be addressed is performance improvements in fiber optic gyroscopes and production and measurement of ultralow degree of polarization (P-10-5). These improvements are also expected to lower the cost and improve maunfacturability and usability of fiber optic gyroscopes by elimination of some components, and substantial reduction of serve performance specifications on others. ***
