Novel fibre optic gyroscope with a configuration combining Sagnac interferometer with fibre ring resonator

A novel fibre optic gyroscope, with a structure making use of the combination of a Sagnac interferometer with an active fibre ring-resonator, is proposed and analysed. The proposed gyroscope can be viewed as a generalised structure of the conventional Sagnac interferometric type fibre optic gyroscope. It has the advantages of both long fibre loop length and multipath interferences. By inserting a fibre amplifier in the loop to provide an optical gain of several dB, the relative maximum sensitivity is enhanced to ~30 times more than that of conventional Sagnac interferometric fibre optic gyroscopes.