Noise Analysis of an Air-Core Fiber Optic Gyroscope

We report the first measurements of the random walk (RW) of an air-core fiber optic gyroscope (FOG), a novel sensor that exhibits reduced thermal sensitivity thanks to the use of an air-core fiber. Comparing this data to the RW-equivalent noise of the gyro detection system alone and to a simple model of detection noise demonstrates that the measured RW is unaffected by the high backscattering of the air-core fiber, but that it is limited instead by detector thermal noise for detected powers under ~5 muW and source excess noise above ~5 muW. Above this power level, the RW is found to be independent of detected power and equal to 0.021deg/radich, which is comparable to and as low as a conventional FOG with a similar scale factor.