Complementary speckle patterns: deterministic interchange of intrincic vortices and maxima throuhg scattering media
Résumé
Intensity maxima and zeros of speckle patterns obtained behind a diffuser are experimentally interchanged by applying a spiral phase delay of charge AE1 to the impinging coherent beam. This transform arises from the expectation that tightly focused beams, which have a planar wave front around the focus, are so changed into vortex beams and vice versa. The statistics of extrema locations and the intensity distribution of the so-generated " complementary " patterns are characterized by numerical simulations. It is demonstrated experimentally that the incoherent superposition of the three " complementary speckle patterns " yield a synthetic speckle grain size enlarged by a factor of ffiffi ffi 3 p. A cyclic permutation of optical vortices and intensity maxima is unexpectedly observed and discussed.
Domaines
Optique / photonique
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