Fig. 1. Schematic of the mode-locked fiber laser based on the NALM. HWP, half-wave plate; PBS: polarizing beam splitter; WDM‐Collimator, a combination of a collimator and wavelength division multiplexer; FR, Faraday rotator; HR, high reflection mirror.

Fig. 2. The average output power as a function of pump 2 power. Pump 1 power was fixed to 650 mW.

Fig. 3. Radio frequency spectrum at the resolution bandwidth of 1 kHz.

Fig. 4. Measured spectra of output pulses. The modulation state of the spectra can be changed by rotating the λ/8 wave plate in the cavity. (a) Highly modulated spectrum, with an output power of 104 mW. (b) Less modulated spectrum, with an output power of 135 mW.

Fig. 5. Fringe-resolved autocorrelation trace of output pulses.

Fig. 6. PICASO retrieved intensity and phase of the output pulse. The retrieved pulse duration is 44.6 fs.