Powerful Sub-40-fs Yb:YAG Thin-Disk Laser Oscillator Operating in the Regime of Strong Self-Phase Modulation

We demonstrate the generation of 29-fs pulses at 2.5-W and 37-fs pulses at 17.1-W average power. This is the highest average power of any sub-50-fs laser oscillator and the shortest pulse duration of any TDL oscillator.