Photorefractive four-wave mixing for optical image restoration

We describe an optical image restoration by using holographic filtering and photorefractive four-wave mixing. A beam generated by four-wave mixing that is, the phase conjugate beam, reads a hologram recorded by a blurred image and blur function where the four-wave mixing process is influenced by an erase beam which has the information of the blur function. We calculate the generation efficiency of the phase conjugate beam and show that the amplitude of the phase conjugate beam can be inversely proportional to the intensity of the erase beam. We also simulate the image restoration by preparing sample images and show that the blur effect can be removed from the distorted image by this method.