Fig. 1. Schematic diagram of PEM structure and its vibration

Fig. 2. Schematic diagram of photoelastic modulation and its calibration system

Fig. 3. Simulation results of vibration and stress of PEM

Fig. 4. PEM with calibration feedback optical path

Fig. 5. Experimental results of resonant frequency test of PEM

Fig. 6. Modulation experiment under different duty ratios

Fig. 7. Calibration coefficient of phase retardation amplitudes between calibration feedback position and central position

Fig. 8. Phase retardation amplitude at calibration position

Fig. 9. Phase retardation amplitude at central position of PEM