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Contrast inversion in the Lau phenomena implemented with a photorefractive grating
It was implemented the Lau effect with a grating registered in a BSO crystal. Two different arrangement were analyzed. In both cases, it is possible to control the visibility and to produce the contrast inversion of fringes, ...
Talbot and Lau phenomena implementation via a photorefractive converter
We propose a novel implementation of the Lau and Talbot effects. It employs a grating registered as modulation of birefringence in a Bi12SiO20 crystal. The systems proposed allow to control the visibility and in particular ...
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 ...
Logic operations by using modulated speckle
An alternative image multiplexing technique is proposed. In the arrangement implemented, the input is imaged by introducing a multiple aperture pupil in the imaging lens. Then, the speckle pattern is modulated by several ...
Features on photorefractive registered speckles
The recording and read-out of a volume speckle pattern is investigated for transmission geometry. The modulation of the 3D speckle grains appears when the image of a coherently illuminated random diffusor is formed onto ...