Retracing behaviours of a BBO optical parametric oscillator pumped with 532 nm laser

The authors report experimental results of the retracing behaviours in a BBO optical parametric oscillator pumped by the second harmonic of a Q-switched Nd:YAG laser. Two sets of signal-idler could be observed in their noncolinear type-I phase-matching configuration in a certain tuning range. Particularly, near the turning point of phase-matching angle, they have implemented simultaneous phase matching for a broad wavelength range. In this situation, the spectral width of the signal output can be as large as 160 nm (740-900 nm), and that of the idler is 590 nm (1.3-1.89 μm). With a tuning setup, such as a grating, broadly tunable coherent sources can be obtained in the above wavelength ranges without a complicated tuning mechanism