Intensity and phase cross talk in degenerate four-wave mixing

Cross talk between two beams incident upon a four-wave-mixing phase conjugator was investigated experimentally as a function of beam input angles and beam intensities for the case when both input beams and the four-wave-mixing pumps were the same frequency. Intensity cross talk in the conjugated return beams was observed. Analysis shows that intensity cross talk arises from a competition for pump intensity that occurs when the sum of the two input probe intensities is more than a few percent of the pumps. A model of this mechanism has been developed that permits quantitative prediction of intensity cross talk.