Fig. 1. (a) Optical fiber F-P sensing system; (b) optical fiber F-P sensor

Fig. 2. Statistics of optical fiber F-P sensor articles indexed by SCI, EI, and CNKI. (a) Number of the articles in recent years; (b) district statistics of the first author

Fig. 3. New method of processing the intrinsic optical fiber F-P cavity. (a) Femtosecond laser irradiation on the side; (b) hollow fiber

Fig. 4. Extrinsic F-P cavity based on microstructure processing technology. (a) Silicon substrate; (b) borosilicate glass and SiO2 diaphragm; (c) SU-8 photoresist

Fig. 5. Micro fabrication of F-P cavity on fiber end face. (a) Treated with femtosecond laser; (b) treated with chemical etch; (c) graphene diaphragm

Fig. 6. Micro-machining of F-P cavity on fiber side face. (a) Femtosecond laser processing; (b) grinding processing

Fig. 7. Fabrication of fiber bubble F-P cavity on hollow fiber. (a) Discharge treatment; (b) formation of bubble

Fig. 8. Fabrication of fiber bubble F-P cavity with oil immersed fiber

Fig. 9. Ideal interference output spectrum of F-P cavity

Fig. 10. Demodulation outputs of interference signal. (a) Fourier transform spectrogram; (b) discrete cavity length conversionresults; (c) correlation demodulation results

Fig. 11. Influence of actual spectrum source on (a) F-P cavity output spectrum, (b) Fourier transform results, and (c) correlation demodulation results

Fig. 12. Principle of demodulation for parallel multiplex F-P cavities. (a) Parallel multiplex of twin F-P cavities; (b) interferometric output signals; (c) Fourier transform spectrum

Fig. 13. Principle of demodulation for series multiplex F-P cavities. (a) Series multiplex of twin F-P cavities; (b) interferometric output signals; (c) Fourier transform spectrum; (d) envelopes of interferometric output signals

Fig. 14. Demodulation system with (a) a spectrometer as a spectral receiver and (b) a high fineness tunable filter as a spectral receiver

Fig. 15. Demodulation system with a swept frequency light source

Fig. 16. Schematic of scanning correlation demodulation system

Fig. 17. Non-scanning correlation demodulation system. (a) System principle diagram; (b) interference fringe of optical wedge; (c) output signal

Fig. 18. Improved correlation demodulation system. (a) Birefringence wedge and polarization detection; (b) inclined incidence and reflection

Fig. 19. Demodulating system for phase modulation. (a) Phase generation carrier; (b) heterodyne; (c) signal processing

Fig. 20. Fiber F-P sensing system for aircraft. (a) Micro fiber F-P pressure sensor; (b) multi-channels fiber F-P demodulation system

Fig. 21. Fiber F-P strain sensor system and its application. (a) Embedded fiber F-P strain sensor for concrete; (b) fiber F-P strain demodulator; (c) its application to structural health monitoring system for long-span bridges