On a Closed-Loop Resonator Fibre Optic Gyro (R-Fog) Employing a Semiconductor Laser
D. Ying, W. Wu, Q. Li, H. Ma and Z. Jin
Using a semiconductor laser instead of a fibre laser, we set up a closed-loop resonator fibre optic gyro (R-FOG) based on digital serrodyne modulation, to minimize the system size, improve the linearity and dynamic range of gyro output. The performance of this R-FOG system is experimentally studied. A gyro bias stability of 7.30 deg/h is achieved and a ±36.00 deg/h rotation response is observed. And either of the bias stability or rotation response is of the same magnitude as that of the closed-loop R-FOG system using fibre laser. As a result of the closed-loop operation, the dynamic range is increased to ±860.00 deg/s, which is four-times that of the open-loop system, and the scale factor nonlinearity is decreased to 770 ppm from 2.670% under open-loop operation. It is concluded that besides greatly minimizing system size, the performance of the system using a semiconductor laser is very close to that using a fibre laser, and compared with the open-loop operation, the closed-loop operation system with a semiconductor laser can also greatly improve the linearity and dynamic range. These experimental results indicate that adopting the laser source of semiconductor laser together with closed-loop operation may be an effective way to realize a high-performance and minimized R-FOG.
Keywords: Resonator fibre optic gyro (R-FOG), semiconductor laser, closed-loop, bias stability, dynamic range, scale factor nonlinearity