中文摘要：

光源附近的空间分辨漫反射与散射介质的高阶光学参量有关．为了研究高阶参量对漫反射的影响，定义了二阶参量灵敏度和三阶参量灵敏度，它们表示了由于高阶参量变化导致漫反射变化的相对量．从P3近似理论出发，推导了二阶参量灵敏度和三阶参量灵敏度的解析表示，并进行了数值分析和比较．研究表明，在大于一个输运平均自由程的非漫射近似区域，反射率随二阶光学参量增加而增加，其灵敏度随着空间变化，并在小于两个输运平均自由程内出现极大值；相比之下，三阶光学参量对漫反射率的影响可以忽略．

英文摘要：

Spatially resolved reflectance close to the source is dependent on high-order optical parameters of the media. In order to investigate the influence of high-order parameters on the diffuse reflectance, we define sensitivities of the spatially-resolved diffuse reflectance to the second- and third-order optical parameters. The sensitivity denotes the relative change of diffuse reflectance due to a change in the optical parameter. Expressions of the sensitivities are derived from P3 approximation theory, and numerical analyses are performed. We show that the sensitivity changes with source-detector separation and reaches a maximum in the region between one transport mean free path and two transport mean free paths, and is positive in the region beyond one transport mean free path. The influence of third-order optical parameter on the diffusing reflectance can be ignored in comparison with the influence of second-order optical parameter.