Comparison on performances of continuous-wave and acousto-optically Q-switched Nd:GdYTaO4 lasers under 808 nm and 879 nm pumping

Abstract

This study investigated the laser performance of a Nd:GdYTaO4 crystal in continuous-wave and acousto-optically Q-switched operation. Laser performance comparison was conducted under 808 nm and 879 nm laser diode (LD) pumping. In continuous-wave operation, the maximum power at 1066 nm reached 4.4 W with an optical-to-optical efficiency of ~33.6% and the slope efficiency was ~35.9% under 808 nm laser diode pumping. In comparison, an output power of 7.7 W with an optical-to-optical efficiency of ~47.8% and a slope efficiency of ~48.3% were achieved in 879 nm LD pumped 1066 nm laser. Under 808 nm LD pumping, the Nd:GdYTaO4 crystal yielded an average output power of 1.1 W and a pulse width of 59.5 ns at the repetition rate of 30 kHz. By using direct pumping directly into the 4F3/2 emitting level, the average power was increased to 1.9 W and the pulse width was shortened to 33.0 ns at the repetition rate of 30 kHz.