Proposal for eliminating the external disturbance via digital PGC technique in a multiplexed fiber interferometer measurement system

We demonstrate a multiplexed fiber interferometer measurement system for eliminating the external disturbance using the digital phase generated carrier (PGC) demodulation technique. By applying two fiber Bragg gratings (FBG) and two fiber interferometers that share the reference arm and part of the sensing arm in this measurement system, we find that the system can be used for detecting the useful signal and the external disturbances is reduced by 26 dB. Thus, our work may provide some new possibilities for technological applications in vibration measurement.