High-power 2 GHz fs pulsed all-fiber amplified laser system at 20 µm

High-power femtosecond (fs)-pulsed all-fiber lasers operating at high repetition rates are highly demanded for various applications, including laser micromachining, nonlinear optical imaging, high-speed optical sampling, arbitrary waveform generation, and frequency metrology. However, their performance has long been limited by either the average power, repetition rate, pulse width, or compactness, which prevent practical applications. In this work, we report a high repetition rate fs-pulsed all-fiber laser at 2.0 µm that so far provides the best performance metrics, to the best of our knowledge, i.e., ∼2GHz fundamental repetition rate, 126 fs pulse width, ∼8W average power, and all-fiber configuration. We anticipate that this laser can be a promising fs-pulsed fiber laser source for applications requiring a GHz repetition rate.