Resonator integrated optic gyro based on multilevel laser frequency lock-in technique

Abstract

The resonator integrated optic gyros (RIOGs) based on the Sagnac effect have gained extensive attention in navigation and guidance systems due to their predominant advantages: high theoretical accuracy and simple integration. However, the problems of losing lock and low lock-in accuracy are the bottlenecks, which restrict the development of digital RIOGs. Therefore, a multilevel laser frequency lock-in technique has been proposed in this Letter to address these problems. The experimental results show that lock-in accuracy can be improved one order higher and without losing lock in a variable temperature environment. Then, a digital miniaturized RIOG prototype (18 cm × 18 cm × 20 cm) has been produced, and long-term (1 h) bias stability of 26.6 deg/h is successfully demonstrated.

Structural non-reciprocity study of optical systems for RFOGs driven by broad-spectrum light sources

“…2. 1, 2, 3, and 4 are the different operating points of the broad-spectrum light source-driven RFOG, and I1, I2, I3, and I4 are the light intensities at the corresponding operating points, which are defined similarly to that of the IFOG [6][7] .The traditional modulation scheme of the broad-spectrum light source-driven RFOG is to modulate the system by the frequency shifting function of the MIOC at the operating points 1 and 2. modulation of the system. In the open-loop state, after the working point is determined, the optical power-frequency conversion coefficient k is also determined, so the light intensity change can be considered to be approximately linear, and at this time the angular velocity Ω can be expressed as:…”