Fig. 1. Development venation of dual-comb ranging

Fig. 2. Time and frequency domain characteristics of dual-comb system. (a) Principle of linear optical sampling in time domain; (b) principle of multimode heterodyne interference in frequency domain

Fig. 3. Schematic of dual-comb ranging system

Fig. 4. Schematic of dual-comb ranging system with orthogonal polarization structure^[56]

Fig. 5. Optimization of repetition rate difference^[54]. (a) Optimal range analysis of repetition rate difference; (b) impact of spectrum aliasing on ranging precision

Fig. 6. Optimization of repetition rate and spectral bandwidth^[54]. (a) Impact of repetition rate on ranging precision; (b) impact of spectral bandwidth on ranging precision

Fig. 7. Synchronous locking of dual-comb system^[73]. (a) System structure; (b) timing jitter before and after noise suppression

Fig. 8. Digital post-correction method of dual-comb noise^[75]. (a) System schematic diagram; (b) Allan deviation of carrier phase jitter and timing jitter

Fig. 9. Principle of dual-comb combined ranging method

Fig. 10. Dual-comb combined ranging method locked to CW reference lasers^[49]. (a) System schematic diagram; (b) Allan deviation (precision) versus averaging time

Fig. 11. Synthetic-wavelength-based dual-comb ranging method^[58]. (a) System schematic diagram; (b) Allan deviation (precision) of three ranging methods versus averaging time

Fig. 12. Principle of multi-pulse linear optical sampling^[81]

Fig. 13. Multi-degree-of-freedom measurement method based on multi-target dual-comb ranging^[59]

Fig. 14. Dual-comb spectroscopy resolved three-degree-of-freedom sensing^[85]. (a) System schematic diagram; (b) schematic of grating-corner-cube sensor

Fig. 15. Instrument of dual-comb ranging. (a) Key components of the instrument; (b)comparison results of ranging

Fig. 16. Schematic of dual-comb line-scan 3D imaging^[38]

Fig. 17. Stability measurement of space camera overall structure

Fig. 18. Satellite antenna measurement

Fig. 19. Schematic of micro-comb dual-comb ranging^[60]