Beam tilt and angular dispersion in broad-bandwidth, nanosecond optical parametric oscillators

We show that the signal and idler beams generated by certain types of unseeded, nanosecond optical paramet ric oscillators are tilted and angularly dispersed and have anomalously large bandwidths. This effect is demonstrated in both laboratory measurements and a numerical model. We show how the optical cavity design influences the tilts and how these tilts can be eliminated or minimized. We also determine the conditions necessary for injection seeding of these parametric oscillators. (C) 1999 Optical Society of America [S0740-3224(99)02409-1].