ELECTROOPTIC CONTROL OF CORRELATIONS IN SPECKLE STATISTICS

We describe an experiment in which the statistical properties of speck le are modified reproducibly through the use of the electro-optic effe ct in a birefringent liquid crystal. By adjustment of the voltage appl ied to a specifically designed liquid-crystal cell, the correlation be tween the ordinary and the extraordinary waves (which are orthogonally polarized) is varied from almost complete correlation to almost compl ete decorrelation. The correlation's statistics vary smoothly between the limits of single-speckle-pattern statistics (complete correlation) and the statistics for the intensity addition of two uncorrelated spe ckle patterns (complete decorrelation). The combined speckle pattern i s observed and compared with theory.