High-power mid-infrared femtosecond master-oscillator power-amplifier Er:ZBLAN fiber laser system

Abstract High-power femtosecond mid-infrared (MIR) lasers are of vast importance to both fundamental research and applications. We report a high-power master oscillator power amplifier laser system consisting single-mode Er:ZBLAN fiber mode-locked pre-amplifier followed by large-mode-area main amplifier. The is actively cooled bidirectionally pumped at 976 nm, generating slope efficiency 26.9%. Pulses 8.12 W, 148 fs 2.8 μm with repetition rate 69.65 MHz achieved. To the best our knowledge, this highest average ever achieved from MIR source. Such compact ultrafast promising for wide range applications, such as medical surgery material processing.