Fig. 1. Schematic diagram of strain calibration principle using microwave delay method

Fig. 2. Strain application device

Fig. 3. Test results and comparison with theoretical calculations of phase strain coefficients. (a) Bare fiber; (b) tight sheathed fiber

Fig. 4. Comparison of calibration measurement results between microwave phase calibration method and BOTDR system. (a)10 m near-end; (b) 20 km far-end

Fig. 5. Measurement accuracy results of phase strain coefficient