Navigation-Grade Laser-Driven Fiber-Optic Gyroscope

The scale factor stability of a fiber-optic gyroscope (FOG) directly depends on the stability of the central wavelength of its optical source. Although broadband highly stable light sources used in high-precision FOGs provide excellent wavelength stability, they are typically bulky, which complicates the miniaturization of FOGs and FOG-based systems. This work investigates the use of a semiconductor laser diode with pulse-frequency current modulation in a navigation-grade FOG. It is shown that this approach provides superior central-wavelength stability (better than 1.6 ppm), resulting in a FOG angle random walk and bias instability of 0.002°/√h and 0.009°/h, respectively. Comparable performance can be obtained in FOGs employing broadband highly stable light sources.