Widely tunable, high-repetition-rate, dual signal-wave optical parametric oscillator by using two periodically poled crystals

This paper reports on a high-repetition-rate dual signal-wave (DSW) optical parametric oscillator (OPO) operating at the 1.5μm band with tunable wavelength intervals from 2.5nm to 69.1nm. Two periodically poled crystals, a periodically poled lithium niobate (PPLN) with multiple gratings and a single grating MgO-doped PPLN (PPMgOLN), are cascaded in the same OPO cavity to generate dual signal-waves by using quasi-phase-matched (QPM) technique. The pump source was a Q-switched diode-pumped Nd:YVO4 laser operating at 50kHz. At an incident pump power of 3W, an average output power of 169.6mW at 1489.2nm and 1558.3nm has been achieved.