Enhanced differential detection technique for the resonator integrated optic gyro.

An enhanced differential detection technique (EDDT) is proposed to suppress common-mode signal and improve detection accuracy of the resonator integrated optic gyro (RIOG). Reciprocity of the RIOG based on a transmissive resonator is effectively promoted by proposing a novel structure, which has the benefit of suppressing the reciprocal error. Theoretical analysis shows the differential-mode output of the EDDT, which is in proportion to gyro angular rotation, can be amplified without the limitation of the RIOG's common-mode signal. The appropriate gain of the EDDT is also calculated by considering intrinsic noises of the RIOG. With the EDDT technique, a long-term bias stability of 0.0029 deg/s is successfully observed over a 2-h timeframe, which, to the best of our knowledge, is the best result reported in the open literature for the open-loop RIOG based on a waveguide ring resonator.