Comparison of a numerical model with measured performance of a seeded, nanosecond KTP optical parametric oscillator

We have constructed a numerical model of seeded optical parametric oscillators that is appropriate for nanosecond or longer pulsed operation. We have also experimentally characterized the performance of a KTP ring optical parametric oscillator. We present a description of the model and show that its predictions agree well with the observed oscillator performance. We compare spatial beam quality, spectra, efficiency, and full-beam and spatially resolved temporal profiles. Backconversion of signal and idler light to pump is found to affect all the aspects of performance.