Theory of phase conjugation with weak scatterers

A theory relating to correction of distortions that may be achieved by phase conjugation is developed on the basis of the first Born approximation. It is shown that, to good accuracy, the effect of a distorting medium on an incident wave is eliminated by phase conjugation if the following conditions are satisfied: the incident field contains no evanescent components, the transmitting medium is a weak, nonabsorbing scatterer, and backscattering of the incident and of the conjugate wave and also the effects of scattered evanescent waves are negligible.