Amplification-free GW-level, 150 W, 14 MHz, and 8 fs, thin-disk laser oscillator

We report an amplification-free thin-disk laser oscillatory system delivering 0.9 GW peak power. The 120 fs pulses at 14 MHz containing 12.8 $\mu$J delivered by thin-disk oscillator were compressed by factor 15 down to 8.0 fs with 148 W average output power and 82 % overall efficiency. Additionally, we showed that even a sub-two-cycle operation with 6.2 fs can be reached with this technology. The system will be a crucial part of the XUV frequency comb being developed and a unique high-repetition rate driver for attosecond pulse generation.