This paper presents analytical modelling for describing the speckle noise decorrelation in phase data from two- or multiple-wavelength digital holography. A novel expression for the modulus of the coherence factor is proposed for the case of two-wavelength speckle decorrelation from imaging roughness and surface shape through an optical system. The expression permits us to estimate the speckle decorrelation phase noise in surface shape measurements. The theoretical analysis is supported by realistic simulations including both the surface roughness and shape. The results demonstrate the very good agreement between the modulus of the coherence factor estimated with the simulation and the one calculated with theory.

中文翻译：

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多波长数字全息中表面形状引起的去相关噪声的理论分析

本文提出了用于描述来自两个或多个波长数字全息术的相位数据中斑点噪声去相关的分析模型。对于通过光学系统成像的粗糙度和表面形状的两波长斑点去相关，提出了一种相干因子模量的新表达式。该表达式使我们能够估计表面形状测量中的斑点去相关相位噪声。理论分析得到包括表面粗糙度和形状在内的逼真的模拟的支持。结果表明，通过仿真估计的相干因子模量与通过理论计算的相干因子模量之间具有很好的一致性。