2-kW all polarization-maintaining fiber ultrafast laser at a GHz repetition rate

In this Letter, we report a 2-kW all polarization-maintaining (PM) fiber ultrafast laser from a single fiber link, which has a center wavelength of 1064 nm and a repetition rate of 1.39 GHz.To the best of our knowledge, this is the highest average power from all PM fiber lasers at 1.0 m.Its beam quality (M 2 ) is measured to be <1.2, and the pulse width after compression is measured to be 855 fs.