Abstract
Optimizing the bias modulation of a fiber-optic gyroscope is crucial to
improving its precision. In this study, we propose and demonstrate the
use of multiple harmonics of sinusoidal modulation as an intermediate
alternative to the widely used modulation methods: sinusoidal and
square-wave modulation. We show that this alternative integrates the
advantages of each modulation method by providing a smooth modulation
that produces a clean, spike-free output and a satisfactory
signal-to-noise ratio. By using three harmonics of modulation in
combination with a high frequency to reduce thermal phase noise, we
obtained an angular random walk of 5.2(2) μdeg/√h and a bias instability
of ∼10 μdeg/h.