Coherent Matrix-Based Approach for Evaluation of First-Order Speckle Intensity Statistics and Its Application for Speckle Suppression

Abstract

The existing approach for evaluating the statistical characteristics of speckle intensity distribution is applicable only to completely decorrelated laser beams. In the current study, a theoretical method based on a coherent matrix is developed for evaluating the first-order speckle statistics of partially correlated beams. A rigorous analytical formula for the calculation of speckle contrast is obtained based on the proposed coherent matrix method. Subsequently, an approximate analysis model of the speckle intensity distribution in a laser spot illuminated by partially correlated beams is proposed. The simulation results show that the accuracy of the approximate analysis model increases with the number of beams and is acceptable for practical application, even for a small number of beams. Applications of the proposed method are presented for analyzing two different optical schemes for speckle suppression. It is shown that the developed theoretical method is straightforward and effective for the analysis of light intensity statistics of laser spots illuminated by partially correlated beams. Therefore, the developed method can be easily generalized to imaging systems with partially correlated laser beams for evaluating the speckle intensity statistics.

Keywords

• Coherent matrix
• first-order speckle intensity statistics
• hadamard matrix
• partially correlated laser beams