Gain-switched watt-level thulium-doped fiber laser and amplifier operating at 1.7 ?m

Abstract A 1.7 ?m gain-switched thulium-doped all-fiber laser with a master oscillator power amplifier (MOPA) configuration, utilizing bandpass fiber filter and 1550 nm erbium/ytterbium-codoped MOPA, is demonstrated. The influences of pump pulse parameters (repetition rate duration) cavity structures (ring linear) on the performances were experimentally investigated. To best our knowledge, quenching drop observed in lasers for first time, resulting from mode-locked-resembling operation nonlinear effects. Moreover, ring-cavity was more stable than linear-cavity time domain power. Finally, maximum average 1.687 W, slope efficiency 19.7%, single-pulse energy 16.87 ?J, width 425 ns, repetition 100 kHz peak 39.69 W obtained.