Fig. 1: Key metrics (yellow diamonds) of a fibre optic gyroscope (FOG) assessed from three performance aspects (labelled in blue, red, and green, respectively).

While practical interferometric fibre optic gyroscopes (IFOGs) have almost reached ultimate performances in short-term noise (e.g., angle random walk, ARW) and long-term bias drift (e.g., bias instability (BI) and bias stability (BS)), further improvements in environmental adaptability—including tolerances to variations of temperature, magnetic field, and radiation—are still under intense investigations, with possible solutions being explored by means of resonant fibre optic gyroscopes (RFOGs) and air-core FOGs. The primary challenge lies in circumventing all the deleterious effects (described in parentheses and in magenta) concurrently.