Kerr-lens mode-locking of an Yb:SrF₂ laser generating 37 fs pulses

We report on the passively mode-locked operation of an Yb:SrF₂ laser generating sub-40 fs pulses at ∼1 μm. By using a high-brightness Yb-fiber laser as the pump source, the Yb:SrF₂ laser delivered soliton pulses as short as 37 fs at 1066.4 nm via soft-aperture Kerr-lens mode-locking, with an average output power of 85 mW at a pulse repetition rate of ∼71.8 MHz. To the best of our knowledge, this is the first demonstration of Kerr-lens mode-locking using the Yb:SrF₂ crystal.