Passive Q-switch mode-locking of 1.34<i>μ</i>m Nd:GdVO₄lasers with Co²⁺:LMA saturable absorber

A diode-end-pumped passively Q-switched mode-locked Nd:GdVO4 laser operating at 1.34 μm by using the Co2+:LaMgAl11O19 (Co2+:LMA) as the saturable absorber in a Z-type cavity has been demonstrated in our experiment for the first time. The repetition rate of the Q-switched pulse envelop increases from 4.2 kHz to 17 kHz as the pump power increases from 3.8 W to 8.9 W, and a maximum Q-switched and mode-locked fundamental mode average output power of 126 mW is obtained. The mode-locked pulse inside the Q-switched pulse has a repetition rate of 114 MHz, and its average pulse width is estimated to be about 280 ps.