Fig. 1. Picture of EFPI sensor

Fig. 2. EFPI sensor reflection spectrum

Fig. 3. EMD decomposition of the reflection spectrum

Fig. 4. (a) Peak before denoising; (b) Peak after denoising

Fig. 5. Reflection spectrum with remainder remove

Fig. 6. Comparison of different types of extreme value demodulation

Fig. 7. Reflection spectrum with phase shift of 0.038 T

Fig. 8. Lissajous ellipse fitted by different phase shifts

Fig. 9. (a) Schematic diagram of pressure experiment system; (b) Field device diagram

Fig. 10. EFPI output interference spectrum under different lateral loads

Fig. 11. Lissajous ellipse fitted with different transverse loads