An Ultrasimplified Two-Axis Interferometric Fiber Optic Gyroscope With Multifunctional Integrated Optics Circuit Sharing

An ultrasimplified two-axis interferometric fiber optic gyroscope (IFOG) is presented, in which all the components are concurrently multiplexed except for the fiber coil. Based on this configuration, we introduce an innovative time-division multiplexing (TDM) scheme. Specifically, by adjusting the length ratio of the two fiber coils and the modulation period, the two axes can be modulated at distinct time segments within single modulation period, thereby enabling the simultaneous operation of the two axes. In comparison to the conventional TDM schemes, the proposed scheme reduces both cost and power consumption, enhances bandwidth, and avoids the loss of valuable data caused by inter-axis switching. Subsequently, an analysis was conducted on the distinctive noise generated by the crosstalk light within this scheme, along with the methods for its suppression. A prototype is manufactured, which achieves the angular random walk of less than 0.378°/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sqrt{h}$</tex-math></inline-formula> and the bias instability of less than 0.236°/h The cost per axis is effectively reduced to approximately 50% of that associated with a single-axis gyroscope with the same configuration.