Fig. 1. Schematics of qDAS system based on wFBG

Fig. 2. Experimental results of reflected light pulse sequence intensity and demodulation signal. (a) Waterfall plot of time-domain intensity; (b) distribution map of PSD along fiber array at 1 kHz

Fig. 3. Simulation results of J02Csinπfmτ value changing with phase modulation amplitude C and modulation frequency f_m in the case of ΔL=1.2 m

Fig. 4. Simulation results of J02Csinπfmτ value changing with phase modulation amplitude C in the cases of ΔL=1.2 m and three modulation frequencies

Fig. 5. Schematic diagram of frequency spectrum of interference pulse

Fig. 6. Simulation results of normalized PSD of Vdc,Rayleigh with phase modulation amplitude C at frequency Δν

Fig. 7. Distribution of PSD along fiber array at 1 kHz of demodulated phase signals under condition of applying cosine phase modulation

Fig. 8. Experimental results on relationship between crosstalk value and magnitude of driving cosinusoidal electrical signal