title: Measurement of reduced backscattering noise in laser-driven fiber optic gyroscopes.
abstract: We report what we believe to be the first demonstration of a laser-driven fiber optic gyroscope (FOG) built with an air-core fiber. Its phase noise is measured to be 130 murad/ radicalHz. When the sensing fiber is replaced with a conventional fiber, this figure drops to 12 murad/ radicalHz. Comparison between these values suggests that the air-core fiber gyro is most likely not limited solely by backscattering noise but by reflections at the solid-core/air-core interface. By minimizing additional noise sources and reducing the air-core fiber loss to its theoretical limit (approximately 0.1 dB/km), we predict that the backscattering noise of the laser-driven air-core FOG will drop below the level of current FOGs. Compared with commercial FOGs, this FOG will exhibit a lower noise, improved thermal and mean-wavelength stability, and reduced magnetic-field sensitivity.
authors.affiliation: Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA. sethlloyd@stanford.edu
authors.forename: Seth W
authors.initials: SW
authors.lastname: Lloyd
authors.forename: Vinayak
authors.initials: V
authors.lastname: Dangui
authors.forename: Michel J F
authors.initials: MJ
authors.lastname: Digonnet
authors.forename: Shanhui
authors.initials: S
authors.lastname: Fan
authors.forename: G S
authors.initials: GS
authors.lastname: Kino