Compact efficient optical parametric generator internal to a Q-switched Nd:YVO₄ laser with periodically poled MgO:LiNbO₃

This paper demonstrates a compact efficient optical parametric generator internal to a Q-switched diode-end-pumped Nd:YVO_4 laser with periodically poled MgO:LiNbO₃(PPMgLN). With the Q-switch set at a repetition rate of 25kHz and the PPMgLN crystal operated at room temperature (25℃), the intracavity optical parametric generator threshold was reached as a diode pump power of 0.9 W. A maximum signal output power of 0.34W with a pulse width of 25 ns and a beam quality factor of 1.4 was obtained at an incident diode power of 3.4 W, leading to a conversion efficiency of 10%with a slope efficiency of 14.4%. By varying the crystal temperature from 25 to 200℃, the output signal wavelengths were tuned in range of 1506--1565 nm. Over a 30-minutes interval, the instability of the signal power was measured to be less than 1%. In addition, the threshold pump intensity for the intracavity optical parametric generator is theoretically investigated, and the obtained result is in good agreement with the experimental results.