Fig. 1. Schematic configuration of the speckle-based WFBGs interrogation system. The inset graph shows four quadratic photosensitive areas of the QD.

Fig. 2. (a) and (b) Speckle patterns and their corresponding reflection spectrum at the temperatures of 20°C, 21°C, 22°C, and 30°C, respectively. (c) WFBG central wavelength as a function of temperature.

Fig. 3. Acquired four QD data traces of the WFBGs.

Fig. 4. (a) Original QD data of FBG#9, with I, II, III, and IV corresponding to the quadrant channels. (b) Repeated measurements of FBG#9 at 15°C for 50 pulses.

Fig. 5. Schematic diagram of the MLP architecture used in this work.

Fig. 6. (a) Training and validation loss reduced during the training epochs. (b) Confusion matrix for the output of the MLP.

Fig. 7. Demodulation results of the dynamic signal at 60 Hz and 100 Hz: (a) the time domain diagram, (b) the corresponding frequency spectrum.