Logic operations by using modulated speckle

An alternative image multiplexing technique is proposed. In the arrangement implemented, the input is imaged by introducting a multiple aperture pupil in the imaging lens. Then, the speckle pattern is modulated by several system of fringes. The input images are sequentially encoded by using a different pupil during each exposure. The pupil arrangements implemented are selected to concentrate in each spot the spectral information corresponding to not more than two exposures. The spectral amplitude components for a pair of exposures are added into the common diffraction spots. All the diffraction spots contain information about a pair of inputs. Then, an image binary operation can be carried out in each spot The technique is implemented by using as recording media photographic films and photorefractive crystals. The BSO crystal as recording medium is quite adequate in the applications proposed because it permits multiple storage in real time., However, due to its volume nature, each speckle grain exhibits angular selectivity in addition to those features observed in bidimensional media (photographic film).