High stability and low harmonic distortion PGC demodulation technique for interferometric optical fiber sensors

Phase generation carrier (PGC) demodulation technique is widely adopted in the field of interferometric optical fiber sensors, for its high sensitivity, good linearity and large dynamic range. In this paper, a novel single-path differential divide PGC demodulation algorithm (PGC-SDD) is designed and analyzed. Experimental results show that not only the distortion induced by light intensity but also the harmonic distortion induced by the modulation depth are well suppressed by the PGC-SDD algorithm. The signal-to-noise and distortion ratio of sensors using the proposed algorithm achieved a gain of 28.06 dB and 13.13 dB over that using differential-cross-multiplying (PGC-DCM) algorithm and PGC Arctangent (PGC-Arctan) algorithm, respectively. In addition, the PGC-SDD demodulation algorithm can also demodulate non-periodic signals.