Stability of single-cavity dual-wavelength-comb fiber laser with significant difference of pulse characteristics

We investigated a stable single-cavity dual-wavelength-comb fiber laser with significant difference of pulse characteristics. Switchable single/dual-wavelength pulses across 1530- and 1550-nm gain regions are obtained by adjusting the intracavity linear loss. In the dual-wavelength operation, the repetition rates fluctuate and drift in more than 145 Hz, while the standard deviation of the repetition rate difference is measured as 64 mHz in 1000-second monitoring. The passive mutual coherence between pulses is comparable or somewhat better than the reported one under the similar disturbance and monitoring condition. Meanwhile, the significant difference of dual-wavelength pulse characteristics, including spectral bandwidth, pulse energy and dispersion is observed and discussed. The qualified stability is also attributed to the significant pulse difference, which could suppress the nonlinear pulse interaction induced instability. These results provide further physical understanding of the construction of dual-wavelength-comb pulse fiber laser, showing the high potential to promote the performance improvement of dual-comb metrology such as dual-comb spectroscopy, and ranging.