Fig. 1. Experimental schematic diagram (a) and physical diagram (b) of FBG spectrum measurement

Fig. 2. Strain distribution nephogram of cantilever beam

Fig. 3. Variation of strain distribution with displacement

Fig. 4. Variation of UFBG reflection spectrum with displacement

Fig. 5. Variation of UFBG reflection spectrum parameters with displacement. (a) Central wavelength; (b) Bandwidth;(c) Peak power; (d) Side mode suppression ratio (SMSR)

Fig. 6. Variation of AFBG reflection spectrum with displacement

Fig. 7. Variation of AFBG reflection spectrum parameters with displacement. (a) Central wavelength; (b) Bandwidth;(c) Peak power; (d) Side mode suppression ratio

Fig. 8. Experimental results of double UFBG displacement measurement. (a) Reflection spectrum; (b) Bandwidth;(c) Temperature compensation

Fig. 9. Experimental results of double UFBG displacement measurement. (a) Reflection spectrum;(b) Central wavelength difference; (c) Temperature compensation