Wavefront structure of light beams in a parametric ring oscillator

The steady-state transverse structure of light beams is determined for a parametric ring oscillator which is formed as a result of self-intersection of a signal light beam in a nonlinear medium. The example of a signal beam with a Gaussian intensity distribution is used to show that the quality of phase conjugation of scattered radiation increases on increase in the intensity of the signal beam above the threshold value.