Flat-topped optical spectrum as a specific marker of multi-pulse grouping in a soliton fiber laser.

We report the experimental observation of a stable generation regime in a soliton fiber laser, characterized by a distinct flat-topped optical spectrum. Notably, in multi-pulse generation, this specific spectrum shape prevents the harmonic mode-locking state, instead connecting the solitons into bound complexes or tight chaotic bunches. Physically, this suggests that in the observed regime, long-range attractive forces dominate over the inter-pulse repulsion across the entire laser cavity.

Supermode noise mitigation and repetition rate control in a harmonic mode-locked fiber laser implemented through the pulse train interaction with co-lased CW radiation: publisher's note.

This publisher's note contains corrections to Opt. Lett.47, 5236 (2022)10.

Resonantly induced mitigation of supermode noise in a harmonically mode-locked fiber laser: revealing the underlying mechanisms.

We have performed experimental and numerical studies enabling clear insight into the physical mechanisms underlying the super-mode noise mitigation in harmonically mode-locked (HML) fiber lasers using the resonant continuous wave (CW) injection. New experiments have refined the requirements to the positions inside the laser spectrum assigned to the injected CW component, a Kelly sideband, and the transparency peaks of the birefringent fiber filter. In particular, we have proved experimentally that the noise mitigation effect is dominating with the CW injected to the long-wavelength side of laser spectrum.

Supermode noise mitigation and repetition rate control in harmonic mode-locked fiber laser implemented through the pulse train interaction with co-lased CW radiation.

We report on new, to the best of our knowledge, techniques enabling both the mitigation of supermode laser noise and highly precise setting of the pulse repetition rate (PRR) in a soliton harmonically mode-locked (HML) fiber laser employing nonlinear polarization evolution (NPE). The principle of operation relies on resonant interaction between the soliton pulses and a narrowband continuous wave (CW) component cooperatively generated within the same laser cavity. In contrast to our recent findings [Opt.

Mitigation of the supermode noise in a harmonically mode-locked ring fiber laser using optical injection.

We report on a new, to the best of our knowledge, technique enabling mitigation of the supermode noise (and timing jitter) in a soliton harmonically mode-locked (HML) fiber laser built on the nonlinear polarization evolution (NPE). An optical injection of an external continuous wave (CW) into the HML laser cavity results in an increase of the supermode noise suppression level (SSL) by a two-three order of magnitude for harmonics between 25th and 135th. The operation mechanism involves phase-locking between the injected light and soliton pulses and exhibits strong resonant dependence on the CW laser wavelength.

Pulse repetition rate tuning of a harmonically mode-locked ring fiber laser using resonant optical injection.

We report on a new, to the best of our knowledge, technique enabling fine-tuning of the pulse repetition rate (PRR) of a soliton harmonically mode-locked (HML) fiber laser built on the nonlinear polarization evolution (NPE). Optical injection of an external continuous wave (CW) into the HML laser cavity is used for this purpose enabling precise PRR tuning with the elementary step equal to the fundamental PRR one-by-one. The effect exhibits strong resonance dependence on the CW laser wavelength and available in both positive and negative directions.