Fig. 1. Block diagram of sensitivity improvement based on reverse LCFBG

Fig. 2. Fiber Bragg Grating Strain Sensing System Based on OCMI and LCFBG Dispersion

Fig. 3. Reflection spectrum and group delay response of LCFBG

Fig. 4. Variation of microwave interference spectrum at axial strain 0 με， 450 με， 950 με

Fig. 5. Microwave interference spectrum drift and fitting curve at 50 μɛ step length

Fig. 6. Microwave interference spectrum drift and fitting curve at 5 μɛ step length

Fig. 7. Test results of different combinations of LCFBG are fitted to the strain curve

Fig. 8. Strain-frequency fitting curve of optical microwave interference without LCFBG

Fig. 9. Change of the measurement reference frequency with the measurement time