Abstract

The theory and practice of optical phase conjugation via degenerative four wave mixing in a nonlinear medium have been standardized for many years. In most of these studies, the role played by the diffracted beam has been largely ignored. Recently, we have shown that in a nonlinear thin medium, under phase-matched conditions, the pump-diffracted beam coupling can give rise to substantial amplification of the probe beam for both local (e.g., Kerr-like) and non-local diffusive (e.g., thermal and electronic) types of nonlinearity,^1,2 The occurrence of these effects, and their magnitude, mandate a reexamination of a similar wave mixing effect, i.e., optical phase-conjugation involving a probe, a pump and another (e.g., retroreflected pump) strong beam. As shown in Figure 1, in the limit of a very weak probe compared to the pump beam, there are altogether six coupled waves, including the three beams mentioned above, the two diffracted beams, and the phase conjugated beam.

© 1988 Optical Society of America