Compact multipass Nd:YVO 4 slab laser amplifier based on a hybrid resonator

The design of a diode stack end-pumped multipass Nd:YVO4 slab laser amplifier based on a stable and off-axis positive-branch confocal unstable hybrid resonator was demonstrated. Without the use of active switching elements, the hybrid resonator of the amplifier permits high multipass amplification of Q-switched laser beams in a compact package. The pulse energy of 3.8mJ and pulse width of 5ns was obtained at a repetition of 1kHz with the amplification factor of 11. In cw operation, the maximum output power of 35.2W was obtained by amplifying the seeder power of 4W. The beam propagation factor M2 in both the cw and pulse models was under 1.3.