Fig. 1. Package structure of the proposed FBG strain sensor

Fig. 2. Preparation process for the FBG strain sensor. (a) Compress jig and its photo; (b) package diagram for sensor components and its photo; (c) sensor in high-temperature thermostat; (d) photo of the FBG strain sensor

Fig. 3. Schematic of the testing device for the proposed FBG strain sensors

Fig. 4. Time-history curves in three loop tensile test for strain performance

Fig. 5. Experimental results. (a)-(c) Six differential outputs of the wavelength shifts; (d)-(f) linear fitting results of average of experimental data

Fig. 6. Test results of temperature compensating capacities for the three sensors

Fig. 7. Time-history curves of creep performance tests of the three sensors