Fig. 1. Schematic diagram of the EOS⁃TD

Fig. 2. Schematic diagram of the non⁃reciprocal π / 2 fixed phase bias unit

Fig. 3. Schematic diagram of the optical frequency comb ranging system based on electro⁃optic sampling

Fig. 4. EOS⁃TD output and calibration of phase detection sensitivity

Fig. 5. Axial resolution Allan deviation

Fig. 6. Calibration of gauge block thickness and laser scanning method

Fig. 7. 500 μm step measurement results

Fig. 8. Surface morphology measurement results of the character "Yuan" on a One⁃Yuan coin

Fig. 9. Dynamic displacement measurement of metal thin film and sound reconstruction

Fig. 10. Comparison of time⁃domain signals

Fig. 11. Comparison of frequency-domain signals