Continuous-wave and femtosecond laser operation of Yb:CaGdAlO_4 under high-power diode pumping

Abstract

We demonstrate the generation of 68 fs secant hyperbolic pulses at a 105 MHz repetition rate with an average power of 520 mW from a diode-pumped Yb3+:CaGdAlO4 mode-locked laser. A semiconductor saturable absorber allows passive mode locking, and a 15 W diode laser is used to pump directly the crystal. To our knowledge this represents the highest average power ever obtained for a sub-100 fs diode-pumped Yb-bulk laser.