Nearly diffraction-limited picosecond pulse amplification from LMA fluoride fiber at 2.8 m

We demonstrated the generation of a nearly diffraction -limited picosecond pulse from a large -mode -area (LMA) fluoride fiber amplifier. Seeded with a mode -locked fiber oscillator at 2.8 mu m, the LMA Er:ZBLAN fiber amplifier delivered the pulse of 16 mu J with a duration of 70 ps at 5 kHz. The nearly diffraction -limited beam was obtained from the 50 mu m LMA fiber using the fundamental mode excitation technique, with a measured M2 value of 1.25 for x axis and 1.27 for y axis, respectively. This high -beam -quality high-energy picosecond fiber -based system of 2.8 mu m exhibits a great potential in the high -precision biomaterial processing. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement