为研究激光经运动漫反射目标后光场统计的特性，结合多像素光子计数器(MPPC)的光子统计模型，并利用光子统计二阶矩和均值，得到描述光子数波动的Fano因子。然后对该因子进行曲线拟合，得到衡量赝热光场光子分布杂乱程度的热模数μ，同时可得衡量探测系统增益系数γ和串扰概率ε的组合参数B。实验结果表明，漫反射目标旋转驱动电压从20 mV逐渐变化到1280 mV，回波光子热模数μ从289增加到1229，且随着电压增大，热模数增长速率逐渐减缓。由于探测器增益γ在实验过程中保持恒定，B参数的变化直接反映探测器像素之间串扰概率的变化，结果表明漫反射目标转速增加，MPPC串扰概率ε减小，通过Fano因子的曲线拟合只给出串扰概率的定性描述，得不到增益系数的相关信息。只有对光子统计三阶矩进行分析，才能获得探测器增益及串扰概率的定量描述。

In order to study the light field statistical property when the laser is scattered by rotated diffuser, combining the statistical model of multi-pixel photon counter (MPPC), the Fano factor which describes the photons fluctuation is gained through adopting the second-order momentum and average value of the photon statistics. Then, the curve fitting of the Fano factor produces the number of thermal modes μ and the parameter B which is the combination of the gain coefficient γ and the cross-talk probability ε for the photo-detector. The experimental results are as follows. The number of thermal modes for the echo signal increases from 289 to 1229 when the driving voltage increases from 20 to 1280 mV, and the increasing speed decreases with the increase of driving voltage for the diffuser. The parameter B can reflect the variance of cross-talk probability between the neighbouring pixels due to the coefficient γ which is a constant during the course of measurement. The results suggest that the cross-talk probability decreases when the rotating velocity increases (the increase of the driving voltage). The curve fitting of the Fano factor only gives the qualitative description of the cross-talk, while there is no information of the gain coefficient in the fitting. The quantitative analysis of gain coefficient and cross-talk probability can be achieved through the research of the third-order momentum for the arriving photons.