Correlation Demodulation for Low- Finesse Fabry-Pérot Sensors Based on Microwave Photonics

Microwave photonics technology is gaining increasing popularity in the realm of optical fiber sensing. A new Fabry-Pérot (FP) correlative demodulation technique combining microwave photonics technology (MWP) and frequency-swept light source (FSL) method is proposed. The demodulation of FP cavity length is operated by the correlation calculations between the interference frequency of the FP sensor and the microwave frequency. The fundamental theory of cross-correlation makes the FSL-MWP method highly resistant to noise. The frequency interval of the microwave signal generator (MSG) and high sweeping rate of the FSL leads to enhanced resolution and precision.