RETRACING BEHAVIORS OF THE PHASE-MATCHING ANGLE IN NONCOLLINEAR PHASE-MATCHED OPTICAL PARAMETRIC OSCILLATORS

We theoretically studied the retracing behaviors of the phase-matching angle in beta-BaB2O4 optical parametric oscillators with noncollinear phase matching when they were pumped with the harmonic of a Nd:YAG la ser. The results imply that two or more sets of signal-idler outputs c an be observed at certain phase-matching angles. Meanwhile, we observe d that over a quite broad signal wavelength range the phase-matching c ondition can be reached simultaneously, leading to an optical parametr ic oscillator of broad signal and idler spectral widths. Experimentall y, with the pump at 532 nm, we observed a two-band signal spectrum, in dicating the simultaneous phase matching of two center phase-matching angles, or retracing behavior. Also, broad idler spectral widths were 145 nm (745-890 nm) and 540 nm (1.32-1.86 mu m), respectively. (C) 199 8 Optical Society of America.