MUTUAL PHASE-CONJUGATION BY THIN-LAYERS

A method for double (or mutual) phase conjugation is proposed that use s two thin layers with a third-order optical nonlinearity; it uses the transformation of phase modulation into amplitude modulation, a techn ique similar to that of a Zernike microscope. The conditions for the b uildup of conjugate waves are above threshold if the modulus of the pr oduct-of the nonlinearities of the two layers is negative and large en ough. The saturated regime and the elimination of nonconjugate waves a re studied theoretically. The possibilities of using liquid crystals a nd multiple quantum wells are discussed.