Fig. 1. Schematic of experimental setup

Fig. 2. Measurement results of laser output when two pulse trains are not isolated. (a) Radio frequency spectrum; (b) pulse trains within 4 ms; (c) pulse trains within 200 ns; (d) optical spectrum

Fig. 3. Laser output measurements after polarization division. (a) Radio frequency spectra (RBW is 27 Hz); (b) optical spectra; (c) radio frequency spectra with multiple harmonics; (d) autocorrelation curve of pulse in each polarization state

Fig. 4. Repetition rate versus time. (a) Repetition rate of pol-1; (b) repetition rate of pol-2; (c) repetition rate difference

Fig. 5. Dual-comb interferograms. (a) Interferogram within 4 ms; (b) local magnification of Fig.5(a)

Fig. 6. Output of dual-comb mode-locked fiber laser when central wavelength is tuned. (a) Repetition rates and repetition rate differences; (b) spectra