Fig. 1. Schematic of the all-fiber sinusoidal phase modulation interferometer

Fig. 2. Displacement measurement simulation

Fig. 3. Kalman filter corrects simulation results

Fig. 4. Phase error introduced by parasitic noise

Fig. 5. Kalman filter corrects simulation results

Fig. 6. Structure of fiber optic interference system

Fig. 7. Comparison of linear measurement range before and after phase modulation

Fig. 8. Experiment result of displacement measurement

Fig. 9. Experimental results of working distance and measurement range

Fig. 10. Repeatability experiment

Fig. 11. Step displacement experiment