Observation of triple-wavelength-comb pulse generation based on the triple soliton formation mechanisms

We proposed the triple-wavelength pulses across the 1530- and 1550-nm gain regions are emitted from a carbon nanotube mode-locked ring fiber laser by simultaneously exploiting intracavity loss-based gain profile tuning, Lyot filter effect, and nonlinear polarization evolution. A polarization beam splitter with 2×1-m intracavity polarization-maintaining fiber pigtails is additionally introduced in a typical ring fiber cavity. Polarization-dependent loss is firstly adjusted to equalize the 1530- and 1550-nm gain regions. Except for the triple-wavelength pulses based on Lyot filter and loss-based gain profile tuning, another type of triple-wavelength pulses, i.e. single-wavelength pulse centered at 1530-nm gain region and spectral-overlapping dual-wavelength pulses centered at 1550-nm gain region, are observed by additionally introducing nonlinear polarization evolution. These intriguing results show the feasibility of multi-wavelength pulse generation based on multiple soliton formation mechanisms and the high potential to construct a single-cavity multiple-comb source with versatile pulse characteristics.