参考光干涉提取复振幅的散斑统计函数的实验研究

由散斑场和参考光的干涉图样提取散斑场复振幅、相位和强度的数值分布，并对其统计特性进行实验研究，消除了散斑场强度统计函数特别是概率密度函数的传统测量方法中噪声引起的偏差，并实现了散斑场复振幅和相位统计特性的实验研究.通过对不同散射角处散斑场的研究发现随着散射角度的增大散斑颗粒逐渐呈现出横向展宽的现象，且其平均宽度表现为各向异性，但是其概率密度函数并没有发生变化，与小角度情况一样属于圆形高斯散斑场.关键词：散斑概率密度干涉

Experimental studies on the statistical functions of speckle fields based on the extraction of the complex amplitudes by use of interference beam

Using the interference patterns of speckle fields and the reference beam, we extract digitally the complex amplitudes, phases and intensities of speckles fields and then study experimentally their properties. The influences of noise on the measurement of statistical functions, especially on that of the probability density function, appearing in the conventional method is satisfactorily eliminated. The experimental studies of the statistical properties of the complex amplitude and the phases of the speckle fields were also performed. By the practical measurement of speckle fields scattered at different angles, we find that the speckles are laterally broadened gradually with increase of the scattering angle, and their average widths become anisotropic. Such anisotropy brings about no change in the probability density function of the speckle fields, which remain circularly Gaussian as in the case of the traditional small angle scattering.