Influence of linear absorption and reflection on the characteristics of four-wave wavefront reversal

An analysis is made of the theory of four-wave wavefront reversal allowing for linear absorption and reflection of all the interacting waves from a mirror which forms a second reference wave from the first incident wave. The Born approximation is used to find the optimum thickness of the nonlinear medium giving the maximum reversal coefficient. Conditions for parametric four-wave oscillation with an arbitrary frequency shift are determined and the dependence of the threshold intensity of the incident reference wave on the linear reflection coefficient of the wave-forming mirror is found for a given thickness of the medium in the absence of absorption.