Continuous self-imaging regime with a double-grating mask.
We analyze the Talbot effect produced by a mask composed of two diffraction gratings. Combinations with phase and amplitude gratings have been studied in the near-field regime. For a two-phase-gratings configuration, the Talbot effect is canceled, even when using monochromatic light; that is, the intensity distribution is nearly independent of the distance from the mask to the observation plane. Therefore, the mechanical tolerances of devices that use the Talbot effect may be improved. In addition, the spatial frequency of the fringes is quadrupled, which improves the accuracy of devices that employ this mask. An experimental verification for the best case two phase gratings, has also been performed, validating the theoretical results.
Sanchez-Brea
Luis Miguel
LM
Optics Department, Applied Optics Complutense Group, Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Ciudad Universitaria s.n., 28040 Madrid, Spain. sanchezbrea@fis.ucm.es
Torcal-Milla
Francisco Jose
FJ
Bernabeu
Eusebio
E
D015350:Contrast Sensitivity; D004867:Equipment Design; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008027:Light; D055095:Optics and Photonics; D010364:Pattern Recognition, Visual; D012031:Refractometry / Q000379:methods*