Eliminating Light Intensity Disturbance With Reference Compensation in Interferometers

Abstract

In this letter, we introduce an improved phase-generated carrier (PGC) demodulation algorithm using reference compensation method to eliminate the influence of light intensity disturbance (LID) in interferometric fiber-optic sensors. In this method, the impacts of LID on acoustic signal and reference signal are the same. The impact of LID on reference signal can be measured via calculating the envelope variation of demodulated reference signal. Then, the impact of LID on acoustic signal is divided off through reference compensation. The improved PGC demodulation algorithm with merit of resisting LID was experimentally demonstrated. The signal-to-noise ratio of demodulation result based on the improved PGC algorithm achieves a gain of 11.78 dB over PGC algorithm using differential-cross-multiplying.