0.5 GHz femtosecond Yb:YAG thin-disk oscillator

Thin-disk oscillators have made significant progress in high power and pulse energy generation, but their ability to achieve high repetition rates is limited, primarily due to the structure of the multi-pass pumping cavity and the requirement for large beam spot sizes within the cavity. In this Letter, we employed an asymmetric cavity structure and used a thin-disk crystal as an end mirror, successfully achieving repetition rates of 432 MHz and 520 MHz in Kerr-lens mode-locked Yb:YAG thin-disk oscillators, with corresponding output powers of 33 W and 36 W and pulse durations of 253 fs and 276 fs, respectively. These results represent the highest, to the best of our knowledge, repetition rates reported for mode-locked thin-disk oscillators to date. Achieving a repetition rate of 1 GHz appears feasible by integrating custom components within the disk pumping module.