Aircraft-navigation-grade laser-driven FOG with Gaussian-noise phase modulation

A laser-driven fiber optic gyroscope (FOG) is demonstrated with an angular random walk noise of 5.5×10^-4  deg/√h, a drift of 6.8×10^-3  deg/h, and an inferred scale-factor stability of 0.15 ppm, making it, to the best of our knowledge, the first laser-driven FOG to satisfy the performance requirements for inertial navigation of commercial aircraft. This is achieved using Gaussian white noise phase modulation to broaden the linewidth of the source laser and to strongly suppress the narrow-linewidth optical carrier. The performance of this laser-driven FOG is shown to have better noise and only slightly higher drift than the same FOG driven by a conventional superfluorescent fiber source. This result is validated for two lasers with widely different intrinsic coherence.