Fig. 1. Convolution results of dot signal and second derivative of normalized Gaussian function. (a) Original signal（s=200）; (b) convolution signal（σ=20）

Fig. 2. Convolution results of dot signal and second derivative of Gaussian function on the different scales. (a) Original signal （s=200）; (b) convolution signal（σ=70）; (c) convolution signal（σ=100）; (d) convolution signal(σ=130)

Fig. 3. Process of peak detection

Fig. 4. Schematic of the experimental platform

Fig. 5. FBG reflection spectrum

Fig. 6. Physical diagram of the experimental platform

Fig. 7. Detection results of three peak-detection algorithms

Fig. 8. Relation between SNR and algorithm error by the three algorithms