Xiaobin XU^*, Fei TENG, Chunxi ZHANG, Ningfang SONG, and Jing JIN

School of Instrument Science and Opto-electronics Engineering, Beihang University, Beijing 100191, China

(Received February 26, 2014; Accepted July 2, 2014)

The dual-interference fiber optical gyroscope (DIFOG) is a novel gyroscope that makes use of both birefringent axes in a polarization maintained fiber to generate two Sagnac interferometers. The Sagnac effect is doubled in the DIFOG, resulting in the same precision for a smaller fiber coil and shorter fiber, so it has some potential applications in miniaturized and low-cost situations. The mechanism of polarization nonreciprocity (PNR) in the DIFOG is investigated and the influence of PNR is analyzed theoretically. Simulation results based on the theoretical analysis indicate that PNR error causes the bias of interference signals and the output of the DIFOG to vary with the inherent nonreciprocal phase that arises from the optical configuration. The experiment verifies the theoretical and simulation results.

Key words: Sagnac effect, fiber optical gyroscope, dual-interference fiber optical gyroscope, polarization nonreciprocity

^*E-mail address: xuxiaobin@buaa.edu.cn