A new approach for determination of a mean speckle size in simulated speckle pattern

•1D correlation method of a long vector for speckle size determination is presented.•The new method and known average 1D correlation method are compared.•No requirement to enlarge the area of speckle pattern detection.•The new method brings more accurate results than the average 1D correlation method.

In this paper one-dimensional correlation method for determination of a mean speckle size is used, while two various approaches are presented. It is shown, that accuracy of the measurement by the method depends on a number of speckles in an evaluated one-dimensional intensity profile of detected speckle pattern. It is also shown, that a significant optimization of the method by reduction of a number of intensity values representing detected speckle patterns can be performed. This study is carried out for several speckle patterns generated through a numerical simulation of the speckle fields after reflection of a Gaussian beam off a rough object’s surface. Results of the determination of the mean speckle size are compared with theoretical predictions.