Ultrashort pulse generation from a passively mode-locked Yb:Sr3Gd2(BO3)4 laser

The spectroscopic properties of a 2 at.% Yb doped Sr3Gd2(BO3)4 (SGB) crystal have been studied in details. With the aid of semiconductor saturable absorber mirror (SESAM), diode-pumped passively mode-locked Yb:SGB laser at 1049 nm was realized, which generated pulses with a minimum pulse duration of 189 fs and a maximum average output power of 177 mW at a pulse repetition rate of 52.2 MHz, corresponding to a single pulse energy of 3.4 nJ and a pulse peak power of 18.1 kW, respectively. Furthermore, pulses as short as 160 fs with an average output power of 124 mW were obtained at 1054.6 nm. To the best of our knowledge, this is the first demonstration of mode-locking laser operation of Yb:SGB crystal.