Photorefractive optical processing: some proposals

Some proposals on Lau and Talbot fringes formation based on a grating registered as birefringence modulation in a photorefractive crystal, will be presented. In the Talbot case, the stored grating can be replicated if read-out with coherent light. The system for the Lau arrangement behaves as a combination of an amplitude and a birefringence phase grating. In both cases, it is possible to control the visibility and to produce a contrast reversion of fringes by using an analyzer. Besides, Lau and Talbot interferometers based on the mentioned approach and their alternative experimental arrangements will be discussed.