A Fiber Optic Accelerometer–Magnetometer

A fiber optic accelerometer-magnetometer (FOAM), which can measure acceleration and magnetic field simultaneously, based on fiber laser sensing is proposed. The principle of the FOAM and the theory of the mixed signal of acceleration and magnetic field are presented. To verify the theory, an FOAM was fabricated and tested. The measured acceleration sensitivity and the sensitivity of magnetic flux intensity were 9.75 pm/g (19.78 dB, re: 0 dB = 1 pm/g) within 100-250 Hz, and 0.955 pm/T/mA@725 Hz, respectively, which were close to the theoretical values. A test of simultaneously measuring acceleration and magnetic field was performed. The results show that the responding mixed signal achieves a good SNR. It proves that the function of the sensor has been realized and the theory of mixed signal is reliable.