  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.
