Fig. 1. Structural diagram of the flow sensor based on the DFB-FL.

Fig. 2. System diagram of flow measurement based on the DFB-FL.

Fig. 3. Frequency response curve of the flow sensor.

Fig. 4. Linear response curve of the flow sensor.

Fig. 5. Flow experiment setup: (a) physical device diagram, (b) structural schematic diagram.

Fig. 6. Time domain demodulation signal with different flows.

Fig. 7. Frequency domain demodulation signal with different flows.

Fig. 8. Relation curves between flow and energy.