Generation of different Pulse States in a nonlinear amplifying Loop Mirror-based 1.7 μm Fiber laser

The 1.7 μm fiber laser with the capability to switch between pulse states exhibits rich pulse dynamics, which not only has significant academic value but also holds broad application prospects, such as in optical fiber communication, optical imaging, and optical signal processing. We designed and experimentally implemented a 1.7 μm fiber laser capable of switching between pulse states that utilized a nonlinear amplifying loop mirror (NALM) for mode-locking. By adjusting the pump power and the polarization state within the cavity, different types of pulses were achieved, including traditional soliton pulses, noise-like pulses, bunched soliton pulses, and soliton rain pulses. Meanwhile, addressing the gap in research on soliton rain in 1.7 μm fiber lasers, a detailed study was conducted on the pulse train length, flow velocity, and flow direction of drifting solitons within the soliton rain. The paper not only enriches the study of pulse dynamics but also has significant academic value and broad application prospects.