Abstract: In a Michelson inteferometer with phase conjugate mirrors at least one of such mirrors includes a Kerr medium. This enables control over the relative phases of the beams that are reflected from the mirrors and superimposed to form an output beam. The interferometer can be used to perform a logic function by interposing transparencies in the reflected beams. By appropriate choice of the relative phases a logic OR function can be achieved.

Abstract: A method of optical phase to amplitude demodulation comprises intersecting two mutually coherent beams of light inside a Kerr medium. One of the beams is unmodulated and the other is phase modulated. The Kerr medium is non-linear and is characterized by an equation n=n.sub.0 +n.sub.2 I, where n is the local refractive index of the medium at a point of interest, n.sub.0 is the linear refractive index of the medium, n.sub.2 is a nonlinear refractive index of the medium and I is the light intensity at the point of interests. An amplitude modulated output beam is generated.