Diode-pumped mode-locked Yb:YCOB laser generating 35 fs pulses

Direct sub-50-fs pulse generation is demonstrated with a mode-locked Yb:YCa4O(BO3)3 laser. With external compression, pulses as short as 35 fs are generated at 1055 nm. The oscillator operating at a repetition rate of 95 MHz is pumped by a two-section distributed Bragg reflector tapered diode laser and mode locked by a semiconductor saturable absorber mirror. The onset of self-Raman-conversion for pulse spectral bandwidths exceeding 40 nm (FWHM) is observed.