The self Q-switching mode-locking effect in compact red fiber laser has been investigated. The Q-switched mode-locking state can keep operating with a pump power ranging from 120.5 mW to 564.8 mW. The maximum average output power of this self Q-switched mode-locking laser is 22.5 mW, and the central wavelength of the output optical spectrum is 635.9 nm with a 3 dB bandwidth of 2.4 nm, as well as the fundamental repetition rate of mode-locking pulse trains being 25.8 MHz. This work can provide an attractive method for Q-switched mode-locking pulse generation in visible fiber lasers.

A wavelength widely tunable all-fiber Tm3+-doped double clad fiber laser by using topological insulator (TI) as saturable absorber (SA), for the generation of large energy passively Q-switched pulse, is demonstrated. This 2 μm fiber laser source can generate an average output power as high as 195 mW, corresponding to a pulse energy of ∼3 μJ, and the laser wavelength can be widely tuned from 1935.42 to 2048.85 nm. This high-performance Q-switched operation is implemented by purpose laser cavity optimization and TI-SA protection. Overall, the above results can provide an easily accessible way to develop large energy wavelength tunable passively Q-switched 2 μm fiber laser sources, which possesses important applications in various fields, including manufacturing, spectroscopy, medicine, and the military.

We report on the investigation of large energy dissipative soliton resonance (DSR) pulse generation in a simple linear cavity Tm 3+ -doped fiber laser (TDFL), by using semiconductor saturable absorption mirror as saturable absorber. This DSR TDFL is implemented by utilizing ultra-high numerical aperture 4 (UHNA4) fiber for dispersion compensation. With further dispersion management, the DSR TDFL can generate an average output power of 242 mW with corresponding pulse energy of ~61 nJ. Moreover, the soliton molecules mode-locked operation has also been demonstrated in this TDFL. Our results can provide an easily accessible way to develop large energy TDFLs.

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