Speckle pattern illumination: Two applications

摘要

The speckle pattern produced by a translucent diffuser which is itself illuminated by another speckle pattern is studied. The decorrelation of the resultant speckle pattern by a lateral displacement of the diffusing surface is shown to be related to the standard deviation of the slope's distribution and to the illuminating speckle grain size. Therefore, measuring the intensity decorrelation as a function of the surface displacement it is possible to obtain information about the diffuser slope distribution. Reciprocally, we show that a statistically characterized diffuser can be used to measure the mean size of the illuminating speckle grain.