Numerical Modelling of the Microcavity OPO
  A detailed description is provided of a numerical model of the microcavity optical parametric oscillator (OPO). The model is solved on a two dimensional grid, in the time domain, using an alternating-direction implicit method. Results are presented for a system pumped with a gaussian spatial profile beam. It is shown that at high pump powers the OPO signal forms a ring, with low emission at the centre where the pumping is strongest. 
D. M. Whittaker