Fig. 1. Experimental structure diagram of FBG

Fig. 2. Transmitted spectrum of FBG with different pressures

Fig. 3. DGD evolution with different pressures

Fig. 4. The maximum DGD amplitude versus pressure

Fig. 5. Pressure measurement system based on FBG

Fig. 6. Variation of the transmission spectra with pressure

Fig. 7. The DGD without pressure

Fig. 8. Variation of the DGD with pressure

Fig. 9. The results of the experiment