%0 Journal Article
%A Torcal Milla, Francisco José
%A Sánchez Brea, Luis Miguel
%A Bernabeu Martínez, Eusebio
%T Near field diffraction of cylindrical convex gratings
%D 2015
%@ 2040-8978
%U https://hdl.handle.net/20.500.14352/35041
%X We analyze the field produced by a cylindrical convex diffraction grating at the Fresnel regime for several kinds of light sources, including a monochromatic quasipunctual source, finite size, and polychromatic sources. These results can help one understand the functioning of rotary optical encoder technology. A decrease in the self-image contrast is produced for finite nonpunctual sources. In addition, the polychromaticity of the source affects the smoothness of the self-images, making them quasicontinuous from a certain distance from the grating forward. Finally, we experimentally validate the obtained analytical predictions.
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