Measurement of χ^(3) and phase shift of nonlinear media by means of a phase-conjugate interferometer

We have constructed a new interferometer that uses two phase-conjugate mirrors. This device allows for the measurement of the relative phase shift and the ratio of the nonlinear susceptibilities of materials. We have been able to measure weak reflectivity signals not detectable by normal degenerate four-wave mixing methods. It has been determined that the x((3)) value of colloid semiconductor glass OG530 at 532 nm is 7 x 10(-12) esu.