Diode-pumped femtosecond Yb:KYW laser with compact three-element cavity

Abstract

We report a highly efficient diode-pumped femtosecond Yb:KYW laser having a compact three-element resonator that incorporates a prismatic output coupler. Near-transform limited pulses of 107fs duration at a centre wavelength of 1056nm are produced at repetition pulse frequency of 294MHz by utilising soft-aperture Kerr-lens mode locking. The femtosecond operation had a mode-locking threshold at a pump power of 250mW and the laser was tunable from 1042nm to 1075nm. The optical-to-optical conversion efficiency exceeded 50% in this femtosecond-pulse regime.