Fig. 1. Schematic diagram of FBG sensing principle

Fig. 2. FBG demodulation system structure diagram

Fig. 3. Photoelectric detection module circuit principle. (a) Photoelectric conversion and amplification circuit; (b) Fourth-order SK low-pass filter circuit; (c) 12 V to 6.2 V; (d) 6.2 V to 5 V

Fig. 4. Flow chart of system demodulation

Fig. 5. FBG demodulation system experiment platform

Fig. 6. Effect of denoising algorithm

Fig. 7. Results of five peak detection algorithms

Fig. 8. Comparison of temperature measurement accuracy results at 37-38 ℃

Fig. 9. Fitting diagram of wavelength and temperature

Fig. 10. Experimental results of system demodulation repeatability

Fig. 11. Experimental results of multi-grating demodulation of the system