Fig. 1. Structure of typical multi-cavity fiber-optic EFPI sensor

Fig. 2. Schematic of the three-wavelength demodulation technology for the interrogation of multi-cavity F-P sensors

Fig. 3. Diagram of interference signals simulation with the center wavelength of 1 548.14，1 550.224，and 1 552.744 nm，respectively

Fig. 4. The simulation results of the demodulation algorithm

Fig. 5. The noise performance of the demodulation system

Fig. 6. The experimental results with initial F-P cavity length of 39.29 μm

Fig. 7. The experimental results with initial F-P cavity length of 64.8 μm