This paper demonstrates a compact efficient optical parametric generator internal to a Q-switched diode-endpumped Nd:YVO 4 laser with periodically poled MgO:LiNbO 3 (PPMgLN).With the Q-switch set at a repetition rate of 25 kHz 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 0.34 W 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 C,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.
This paper reports a continuous-wave (CW) mid-infrared intracavity singly resonant optical parametric oscillator based on periodically poled lithium niobate (PPLN) pumped by a diode-end-pumped CW Nd:YVO 4 laser. Considering the thermal lens effects, it adopted an optical ballast lens and the near-concentric cavity for better operation. At the PPLN's grating period of 28.5 μm and the temperature of 140 C, the maximum idler output power of 155 mW at 3.86 μm has been achieved when the 808 nm pump power is 8.5 W, leading to an optical-to-optical conversion efficiency of 1.82%.
