Generation of 73 fs pulses from a diode pumped Kerr-lens mode-locked Yb:YCa₄O(BO₃)₃ laser

We realized a stable Kerr-lens mode-locked operation in a Yb:YCa₄O(BO₃)₃ laser. Pulses as short as 73 fs were generated at the central wavelength of 1043 nm, with a bandwidth of 19 nm. The femtosecond oscillator operating at a repetition rate of 110 MHz delivers an average output power of 70 mW under 3 W diode pump power. To the best of our knowledge, this is the first demonstration of a pure Kerr-lens mode-locked operation in a diode-pumped Yb:YCa₄O(BO₃)₃ laser.