Widely tunable mid-infrared optical parametric oscillator based on a multiple periods MgO:PPLN

In this paper, we presented a widely tunable Mid-IR OPO based on a single multiple periods MgO:PPLN crystal, acousto-optical (AO) Q-switched Nd:YVO4 laser pumped by 880 nm laser diode (LD) was used as the pumping source. The OPO was designed as an extracavity single resonant optical parametric oscillator. When the grating period of the MgO:PPLN crystal was 31.5 μm and working temperature of 100 °C, and the pump power was 10.95 W with repetition rate of 50 kHz, the single wavelength of 1.72 μm and idler wavelength of 2.78 μm was obtained respectively, the maximum average output power of the parametric lasers was 3.02 W, the pulse width of 7.9 ns was achieved. The optic-optic conversion efficiency was 27.58% from the 1064 nm pump laser to the parametric lasers. By tuning the grating period (28.5~31.5 μm) and the working temperature (25~192.1°C) of the MgO:PPLN, the single laser can be tuned from 1.46 μm to 1.72 μm, the corresponding idler laser can be tuned from 2.40 μm to 4.17 μm. Keywords: Optical parametric oscillator; Quasi-phase-matching; multiple periods MgO:PPLN; Mid-infrared. © 2014 SPIE