Efficiency of wavefront reversal of optical beams in four-wave interactions in a resonant medium

Ail analysis is made of reversal of the phase front of an optical beam in four-wave interaction in a resonant medium. Expressions are obtained for the amplitudes of the signal and reversed beams. It is shown that the reversal coefficient does not depend on the sign of the frequency detuning and may be much greater than unity at pump powers not exceeding the saturation power of the resonance transition.