Thulium-doped fibers with very large mode-field areas offer new opportunities for the power scaling of mid-IR ultrashort-pulse laser sources. The current single-channel laser system presented herein delivers a pulse-peak power of 2 GW and a nearly transform-limited pulse duration of 200 fs in combination with 28.7 W of average power. A tenfold improvement in peak power has been achieved by optimizing the pulse shape and by mitigating atmospheric water absorption. Ongoing efforts include the full exploitation of the thulium-gain bandwidth and the coherent combination of multiple amplifier channels aiming for peak powers of 20 GW at MHz repetition rate in the near future.
© 2016 Optical Society of AmericaPDF Article