Experimental and numerical study of different mode-locking techniques in holmium fiber laser with a ring cavity

Experimental and numerical study has been performed for three techniques of modelocking in all -fiber Holmium laser. We have compared the fundamental repetition rate pulsed generation for mode -locking based on: nonlinear polarization evolution, polymer -free singlewalled carbon nanotubes, and hybrid mode -locking. Experimental and numerical simulation results demonstrated the shortest pulse duration and maximum spectrum width for mode -locking based on the nonlinear polarization evolution: 1.3 ps, 4.2 nm and 1.3 ps, 4.1 nm, respectively. The self-starting mode in this case can vary depending on external conditions in the experiment. In Ho -doped fiber laser with polymer -free single -walled carbon nanotubes mode -locking, the small modulation depth of saturable absorption leads to a long time period of stationary single -pulse lasing development (about 10 4 cavity roundtrips in simulation, and :=1 5 s in the experiment). Both experimental and numerical studies have indicated that a Ho -doped fiber laser with hybrid mode -locking provides optimal generation, enabling self-starting and a relatively fast transition to stable single -pulse lasing (less than 1.5 x 10 3 cavity roundtrips in simulation, and :=1 3 s in experiment). This study presents the first employment of polymer -free single -walled carbon nanotubes for hybrid mode -locking in a Ho -doped fiber laser. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement