A novel interferometric fiber-optic magnetometer with double digital closed-loop detection scheme

A novel interferometric fiber-optic magnetometer with double digital closed-loop detection scheme is presented in this paper. The particular design of optical circuit is performed to the conventional Michelson interferometer based fiber-optic magnetometer. The digital correlation detection technique with double closed-loop is applied to demodulate the weak magnetic field. One digital closed-loop with square-wave phase modulation is realized to eliminate the low-frequency environmental phase drift. The other is utilized to suppress the hysteresis effects of the magnetostrictive material and recover the magnetic field to be measured. Simulation results on the digital closed-loop algorithms verify the feasibility of the proposed scheme.