Fig. 1. Schematic of principle of vibration measurement. (a) Schematic of principle of improved Michelson interferometry; (b) schematic of Fraunhoffer double-slit diffraction

Fig. 2. Relative light intensity of fringe at different phase difference. (a) Phase difference is 0; (b) phase difference is π/2; (c) phase difference is π; (d) phase difference is 3π/2

Fig. 3. Schematic of change in position of brightest stripe. (a) (c) (e) Brightest stripes move from left to right; (b) (d) (f) brightest stripes move from right to left

Fig. 4. Relationship between relative light intensity distribution of interference fringe and width of slit on focal plane. (a) Slit width is 0.05 mm; (b) slit width is 0.10 mm; (c) slit width is 0.15 mm; (d) slit width is 0.20 mm

Fig. 5. Light intensity distribution of interference fringe of focusing lens at different focal lengths

Fig. 6. Influence curves of CCD image acquisition speed on measurement accuracy

Fig. 7. Schematic of extraction method of brightest stripe position

Fig. 8. Reduction results of signal restoration at 500 nm amplitude. (a) PZT input signal; (b) Fourier transform of input signal; (c) time-vibration amplitude measurement result; (d) Fourier transform result of vibration signal

Fig. 9. Vibration measurement results of sample holder. (a) Time-vibration curve; (b) Fourier transform result of vibration signal