Kerr-lens mode-locking of an Yb:SALLO laser generating 25 fs pulses at 1090 nm

We report on the generation of sub-30 fs pulses from a Kerr-lens mode-locked ytterbium solid-state laser based on a disordered Yb:SrLaAlO4 (Yb:SALLO) crystal as a gain medium. The Yb:SALLO laser, pumped by a spatially single-mode Yb-fiber laser at 979 nm, produces soliton pulses as short as 25 fs at 1090 nm, with an average output power of 149 mW at a pulse repetition rate of ∼80.7 MHz. The power scaling potential of the Kerr-lens mode-locked laser is exploited by achieving watt-level (1.54 W) average output power at 1081 nm for a somewhat longer pulse duration of 34 fs. This result corresponds to an impressive laser efficiency of 49.7% and a peak power of 468 kW.