Influence of parametric diffraction on conversion efficiency in two-beam-pumped optical parametric amplifier

We investigate theoretically the parametric diffraction effect in the two-beam-pumped optical parametric amplifier. The analytical solutions for the signal as well as diffracted beams in the linear regime are obtained. We demonstrate that at large intersection angles the parametric diffraction can be suppressed simultaneously with an increase of conversion efficiency to signal beam when the seed intensity is combined with an intensity of the pump beams. The analytical results are in good agreement with the numerical simulations.