Calculation of Rayleigh backscattering noise in fiber-optic gyroscopes

Rayleigh backscattering noise in fiber-optic gyroscopes is calculated by taking into account the Rayleigh backscattered wave phases. The property of a low-coherence light wave is introduced by means of the analytic signal of the light source. The noise-equivalent rotation rate of Rayleigh backscattering is shown to be a factor of 2|1−2K| smaller than the value previously reported, where K is the power-splitting ratio including the effect of fiber loss in the sensing loop.