260 MHz, MW-level thin-disk oscillator

The average power and the pulse energy achieved directly from mode-locked disk oscillators [1] have been substantially increased over the last years approaching the output of amplifier-systems [2-4]. Average power scaling through the increase of repetition rate is in particular important for spectroscopy applications. The thin-disk technology combined with Kerr-lens mode-locking (KLM) is an excellent platform for oscillators with high average power (>100 W) and repetition rates in the few hundred MHz to GHz regime. Such parameters are extremely attractive for UV-XUV and MIR frequency comb spectroscopy, considering the high photon flux of the nonlinearly converted radiation and the enhanced power per mode at a high repetition rate. However, the highest repetition rate of a mode-locked thin-disk oscillator is only 81 MHz currently [5] and no attempt was reported to scale this repetition rate towards the GHz frontiers. Here, we report on a KLM thin-disk Yb:YAG oscillator delivering 215-fs pulses at an average power of 75 W and a repetition rate of 260 MHz. This is a 6.5 times increase of the repetition rate compared to our previous KLM thin-disk result [6].