PGC modulation based on PZT for fiber interferometeric sensor

The phase generated carrier (PGC) modulation-demodulation technique is the main demodulation technique for fiber interferometric sensors. There are two methods to realize PGC modulation. One method is inner modulation, and the other is external modulation. However, there is less study on the PGC external modulation than the PGC inner modulation. In this paper, we focus on the PGC external modulation to analyze its characteristics. The experiment results indicate that the external demodulation performs well. Furthermore, its cost is much lower than that of inner modulation.