High-Average-Power Nanosecond Quasi-Phase-Matched Single-Pass Optical Parametric Generator in Periodically Poled Lithium Niobate

A pulsed nanosecond optical parametric generator (OPG) in periodically poled lithium niobate (PPLN) crystal is presented. The pump laser is an acousto-optically Q-switched Nd:YVO4 laser with the maximum average power of 6.58 W. When the repetition rate is 50 kHz and the pulse width of the pump source is 80 ns, the maximum average total output power of the single-pass PPLN OPG is about 1.9 W, which includes 1.322 W of 1.536 μm signal radiation. The length of the PPLN crystal is only 38.7 mm (at room temperature) with a grating period of 28.93 μm (at room temperature). The 1.502–1.536 μm signal radiation and 3.652–3.465 μm idler radiation are obtained by adjusting the PPLN crystal temperature from 155 degrees C to 250 degrees C.