High peak power sub-60 fs Yb:KGW laser

A high power sub-60 fs mode-locked diode-pumped Yb: KGW laser based on hybrid action of an InGaAs quantum-dot saturable absorber mirror and Kerr-lens mode locking was demonstrated. The laser delivered 56 fs pulses with 1.95 W of average power corresponding to 450 kW of peak power. The spectral bandwidth of the pulse was 20.5 nm, which was near the gain bandwidth limit of the Yb:KGW crystal. To the best of our knowledge, these are the shortest pulses generated from the monoclinic double tungstate crystals (and Yb:KGW laser crystal in particular) and the most powerful in the sub-60 fs regime. At the same time they are also the shortest pulses produced to date with the help of a quantum-dot-based saturable absorber.